Index: src/java/org/apache/ivyde/eclipse/cpcontainer/IvyClasspathUtil.java
===================================================================
--- src/java/org/apache/ivyde/eclipse/cpcontainer/IvyClasspathUtil.java	(revision 744695)
+++ src/java/org/apache/ivyde/eclipse/cpcontainer/IvyClasspathUtil.java	(working copy)
@@ -59,12 +59,19 @@
      */
     public static void addCPContainer(IJavaProject project, IPath projectRelativePath, String confs) {
         try {
+            IClasspathEntry[] entries = project.getRawClasspath();
+            List newEntries = Arrays.asList(entries);
+            // don't add if ivy classpath already exists
+            for (int i = 0; i < newEntries.size(); i++) {
+                IClasspathEntry entry = (IClasspathEntry) newEntries.get(i);
+                if (entry.getPath().segment(1).equals(IvyClasspathContainer.CONTAINER_ID)) {
+                    return;
+                }
+            }
+
             IClasspathEntry newEntry = JavaCore.newContainerEntry(new Path(
                     IvyClasspathContainer.CONTAINER_ID).append(projectRelativePath).append(confs));
 
-            IClasspathEntry[] entries = project.getRawClasspath();
-
-            List newEntries = new ArrayList(Arrays.asList(entries));
             newEntries.add(newEntry);
             entries = (IClasspathEntry[]) newEntries
                     .toArray(new IClasspathEntry[newEntries.size()]);