diff --git a/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/projectmodel/tests/CProjectDescriptionSerializationTests.java b/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/projectmodel/tests/CProjectDescriptionSerializationTests.java
index 9274031de4e..093b80f7561 100644
--- a/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/projectmodel/tests/CProjectDescriptionSerializationTests.java
+++ b/build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/projectmodel/tests/CProjectDescriptionSerializationTests.java
@@ -18,8 +18,10 @@ import junit.framework.TestSuite;
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.model.CoreModel;
 import org.eclipse.cdt.core.settings.model.ICConfigurationDescription;
+import org.eclipse.cdt.core.settings.model.ICFolderDescription;
 import org.eclipse.cdt.core.settings.model.ICProjectDescription;
 import org.eclipse.cdt.core.settings.model.ICProjectDescriptionManager;
+import org.eclipse.cdt.core.settings.model.ICResourceDescription;
 import org.eclipse.cdt.core.settings.model.extension.CConfigurationData;
 import org.eclipse.cdt.make.core.MakeCorePlugin;
 import org.eclipse.cdt.managedbuilder.core.IConfiguration;
@@ -30,12 +32,15 @@ import org.eclipse.cdt.managedbuilder.internal.core.Configuration;
 import org.eclipse.cdt.managedbuilder.internal.core.ManagedBuildInfo;
 import org.eclipse.cdt.managedbuilder.internal.core.ManagedProject;
 import org.eclipse.cdt.managedbuilder.testplugin.BuildSystemTestHelper;
+import org.eclipse.cdt.managedbuilder.testplugin.ManagedBuildTestHelper;
+import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IWorkspace;
 import org.eclipse.core.resources.IWorkspaceDescription;
 import org.eclipse.core.resources.IWorkspaceRoot;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.QualifiedName;
 /**
  * Creates a project in a loop and checks that it is created with appropriate number
@@ -206,4 +211,60 @@ public class CProjectDescriptionSerializationTests extends TestCase {
 		}
 	}
 
+	public void testResetDefaultSetings_Bug298590() throws Exception {
+		String pluginProjectTypeId = "cdt.managedbuild.target.gnu.cygwin.exe";
+
+		CoreModel coreModel = CoreModel.getDefault();
+		ICProjectDescriptionManager mngr = coreModel.getProjectDescriptionManager();
+		
+		String projectName = getName();
+		String folderName = "Folder";
+		
+		// Create a managed project and a folder
+		IProject project = ManagedBuildTestHelper.createProject(projectName, pluginProjectTypeId);
+		IFolder folder = ManagedBuildTestHelper.createFolder(project, folderName);
+		IPath folderPath = folder.getProjectRelativePath();
+		
+		// Initial project description after creating the project
+		ICProjectDescription initialProjectDescription = mngr.getProjectDescription(project);
+		assertNotNull("createDescription returned null!", initialProjectDescription);
+		assertEquals(2, initialProjectDescription.getConfigurations().length);
+		
+		{
+			// No folder description initially as it does not have any custom settings
+			ICConfigurationDescription cfgDescription = initialProjectDescription.getConfigurations()[0];
+			ICResourceDescription rcDescription = cfgDescription.getResourceDescription(folderPath, true);
+			assertNull(rcDescription);
+		}
+
+		// Properties window: get project description: prjd
+		ICProjectDescription propertyProjectDescription = CoreModel.getDefault().getProjectDescription(project);
+		{
+			// Still no folder description
+			ICConfigurationDescription cfgDescription = propertyProjectDescription.getConfigurations()[0];
+			ICResourceDescription rcDescription = cfgDescription.getResourceDescription(folderPath, true);
+			assertNull(rcDescription);
+
+			// getResDesc() creates default folder description
+			ICFolderDescription parentDescription = (ICFolderDescription)cfgDescription.getResourceDescription(folderPath, false);
+			assertEquals("/", parentDescription.toString());
+			ICFolderDescription folderDescription = cfgDescription.createFolderDescription(folderPath, parentDescription);
+			assertEquals(folderPath,folderDescription.getPath());
+		}
+		
+		// OK button, persist the property project description prjd.
+		coreModel.setProjectDescription(project, propertyProjectDescription);
+		
+		{
+			// Folder description should be null as no custom settings were defined
+			ICProjectDescription prjDescription = mngr.getProjectDescription(project);
+			ICConfigurationDescription cfgDescription = prjDescription.getConfigurations()[0];
+			ICResourceDescription rcDescription = cfgDescription.getResourceDescription(folderPath, true);
+			assertNull(rcDescription);
+		}
+
+		// Close project
+		project.close(null);
+	}
+
 }
diff --git a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CProjectDescriptionManager.java b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CProjectDescriptionManager.java
index 7e34793fd05..e63b7e1576a 100644
--- a/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CProjectDescriptionManager.java
+++ b/core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CProjectDescriptionManager.java
@@ -2493,7 +2493,7 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 					parent = parent.getParentContainer()) {
 					// no body, this loop is to find the parent
 				}
-				if(!settingsCustomized(project, (CFolderData)parentRcData, (CFolderData)childRcData)){
+				if(!settingsCustomized(project, (CFolderData)parentRcData, (CFolderData)childRcData, parent.isRoot())){
 					try {
 						data.removeResourceData(childRcData);
 						child.remove();
@@ -2519,35 +2519,33 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 		return modified;
 	}
 
-	static boolean settingsCustomized(IProject project, CFolderData parent, CFolderData child){
+	static private boolean settingsCustomized(IProject project, CFolderData parent, CFolderData child, boolean isParentRoot){
 		if(baseSettingsCustomized(parent, child))
 			return true;
 
 		CLanguageData[] childLDatas = child.getLanguageDatas();
 		CLanguageData[] parentLDatas = parent.getLanguageDatas();
 
-		if(childLDatas.length != parentLDatas.length)
+		// Note that parent-root can define more languages than regular folder where tools are filtered
+		if(!isParentRoot && childLDatas.length != parentLDatas.length)
 			return true;
 
-		if(childLDatas.length != 0){
-			HashMap<HashSet<String>, CLanguageData> parentMap = createExtSetToLDataMap(project, parentLDatas);
-			HashMap<HashSet<String>, CLanguageData> childMap = createExtSetToLDataMap(project, childLDatas);
-			CLanguageData parentLData, childLData;
-			for (Map.Entry<HashSet<String>, CLanguageData> entry : parentMap.entrySet()) {
-				childLData = childMap.get(entry.getKey());
-				if(childLData == null)
-					return true;
+		HashMap<HashSet<String>, CLanguageData> parentMap = createExtSetToLDataMap(project, parentLDatas);
+		HashMap<HashSet<String>, CLanguageData> childMap = createExtSetToLDataMap(project, childLDatas);
+		for (Map.Entry<HashSet<String>, CLanguageData> childEntry : childMap.entrySet()) {
+			CLanguageData parentLData = parentMap.get(childEntry.getKey());
+			if(parentLData == null)
+				return true;
 
-				parentLData = entry.getValue();
-				if(!langDatasEqual(parentLData, childLData))
-					return true;
-			}
+			CLanguageData childLData = childEntry.getValue();
+			if(!langDatasEqual(parentLData, childLData))
+				return true;
 		}
-
+		
 		return false;
 	}
 
-	static boolean settingsCustomized(IProject project, CResourceData parent, CFileData child){
+	static private boolean settingsCustomized(IProject project, CResourceData parent, CFileData child){
 		if(baseSettingsCustomized(parent, child))
 			return true;