WF triggers but not writing to Event Queue

Hello All,

My WFs are triggering but they have stopped writing to the Event Queue.  I have modified the Work Flow to write to other Queues but same result.  I know the WFs are working because I am receiving an email notification.  

Is there a limit on the # of times you can write to a Queue?  # of transactions in the queue is 0.  Any ideas or suggestions will be greatly appreciated. 

Thanks,

GH