Redundant Case Creation Responses

Anytime a case is opened with tech support a canned response is immediately sent out and added to the case:

"Thank you for submitting your questions to us.  Case#<case number>: <case description snippet> has been created."

Recently I've been noticing new copies of this message being are being sent out and added to already open cases.  Initially I thought maybe the case had been reassigned to a new TSE, but that does not appear to be the reason.  Today I escalated a different case, and as soon as I hit the 'Save' button on the escalate form I was sent another one of these 'new case' messages (for my already existing case.)  I'm wondering if maybe there is a bug somewhere that is triggering these new case messages to be sent out when they shouldn't be.  I do have the 'ref' numbers from the messages if someone want to track them down.  Thanks.