Make additional check to prevent trying to load the Deployment descriptor when the project is out of sync.

diff --git a/plugins/org.eclipse.jst.jee.ui/src/org/eclipse/jst/jee/ui/internal/navigator/JEE5ContentProvider.java b/plugins/org.eclipse.jst.jee.ui/src/org/eclipse/jst/jee/ui/internal/navigator/JEE5ContentProvider.java
index 138335e..e644366 100644
--- a/plugins/org.eclipse.jst.jee.ui/src/org/eclipse/jst/jee/ui/internal/navigator/JEE5ContentProvider.java
+++ b/plugins/org.eclipse.jst.jee.ui/src/org/eclipse/jst/jee/ui/internal/navigator/JEE5ContentProvider.java

@@ -83,7 +83,7 @@
 	protected AbstractGroupProvider getCachedContentProvider(IProject project) {
 		AbstractGroupProvider provider = groupContentProviders.get(project);
 		if (provider == null){
-			if (project == null || !project.isAccessible()){
+			if (project == null || !project.isAccessible() || !project.isSynchronized(IResource.DEPTH_INFINITE)){
 				return null;
 			}
 			// if the project is no longer a valid flexible project (due to deletion of critical files)