We had an existing working CQ->RTC one-way synchronization. CQ and RTC servers were upgraded but we were able to verify that the synchronization was still working after.  Since we are changing our process, the sync rule needs to be totally overhauled.  I exported out the original rule and for starters, created a simple new sync rule for a different RTC work item type.  Also updated the CQ Synchronization Filter query in ClearQuest with a test set of records to be synched with the new rule.  Tried to delete the old sync rule and it would not delete - would get 25% of the way through and hang, only to freeze upon cancellation.  Since these changes, nothing is synchronizing, and there are no errors present in client or tomcat logs.  I've tried stopping and restarting the Apache service and always reset the gateway when updating the sync rule. CQ Status page is reporting as it should but with 300 change events not processed under Polling Information.  Every troubleshooting guide I run, everything checks out. Because of these difficulties, we even imported back in the old sync rule and narrowed it down to only the required mappings but still no luck.