Backported fix for bug 159699 - reviewed by Dirk.
diff --git a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java
index 2ee8326..008ed53 100644
--- a/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java
+++ b/org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/java/ContentAssistProcessor.java
@@ -189,7 +189,7 @@
 					extension.setStatusLineVisible(false);
 					if (extension instanceof IContentAssistantExtension3) {
 						IContentAssistantExtension3 ext3= (IContentAssistantExtension3) extension;
-						((ContentAssistant) ext3).setRepeatedInvocationTrigger(KeySequence.getInstance());
+						((ContentAssistant) ext3).setRepeatedInvocationTrigger(null);
 					}
 				}
 			}