### Eclipse Workspace Patch 1.0
#P org.eclipse.jdt.core
Index: model/org/eclipse/jdt/internal/core/ClasspathEntry.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/ClasspathEntry.java,v
retrieving revision 1.128
diff -u -r1.128 ClasspathEntry.java
--- model/org/eclipse/jdt/internal/core/ClasspathEntry.java	14 Feb 2011 04:50:02 -0000	1.128
+++ model/org/eclipse/jdt/internal/core/ClasspathEntry.java	12 Sep 2011 22:19:00 -0000
@@ -1827,6 +1827,7 @@
 	 * @return a java model status describing the problem related to this classpath entry if any, a status object with code <code>IStatus.OK</code> if the entry is fine
 	 */
 	public static IJavaModelStatus validateClasspathEntry(IJavaProject project, IClasspathEntry entry, boolean checkSourceAttachment, boolean referredByContainer){
+		JavaModelManager.getJavaModelManager().resetInvalideArchivesListCache();
 		IJavaModelStatus status = validateClasspathEntry(project, entry, null, checkSourceAttachment, referredByContainer);
 		// https://bugs.eclipse.org/bugs/show_bug.cgi?id=171136 and https://bugs.eclipse.org/bugs/show_bug.cgi?id=300136
 		// Ignore class path errors from optional entries.
Index: model/org/eclipse/jdt/internal/core/JavaModelManager.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.jdt.core/model/org/eclipse/jdt/internal/core/JavaModelManager.java,v
retrieving revision 1.469
diff -u -r1.469 JavaModelManager.java
--- model/org/eclipse/jdt/internal/core/JavaModelManager.java	23 Aug 2011 18:04:23 -0000	1.469
+++ model/org/eclipse/jdt/internal/core/JavaModelManager.java	12 Sep 2011 22:19:01 -0000
@@ -3881,6 +3881,10 @@
 	public void resetClasspathListCache() {
 		if (this.nonChainingJars != null) 
 			this.nonChainingJars.clear();
+		resetInvalideArchivesListCache();
+	}
+
+	public void resetInvalideArchivesListCache() {
 		if (this.invalidArchives != null) 
 			this.invalidArchives.clear();
 	}