Shirt Pocket Discussions - Connection refused error

Not sure if this is directly related to the 10.8.4 update, but upon launching SuperDuper! 2.7.1 (v91) on my Mac Pro 3,1 I now get this pair of errors in Console

Code:

6/7/13 11:43:20.458 AM SuperDuper![67932]: Got disconnected: Error Domain=NSPOSIXErrorDomain Code=61 "Connection refused" UserInfo=0x364c700 {NSLocalizedFailureReason=Error in connect() function, NSLocalizedDescription=Connection refused}

6/7/13 11:43:20.459 AM SuperDuper![67932]: <GrowlGNTPRegistrationAttempt: 0x27e07a0> failed because Error Domain=NSPOSIXErrorDomain Code=61 "Connection refused" UserInfo=0x364c700 {NSLocalizedFailureReason=Error in connect() function, NSLocalizedDescription=Connection refused}

Easy for me to reproduce; I just quit SuperDuper! and then launch it again.

I see Growl is implicated in the second error. I do have Growl 2.0.1 running, however it appears to be functioning normally and no other programs have caused it to issue errors (at least not that I have noticed).

In spite of the errors, SuperDuper! behaves normally after launch. It also executes scheduled backups successfully (after throwing the above errors upon scheduled launch).

Ideas? Not sure if this is just my system or perhaps widespread.

Thanks!