No, I did not need to pull any battery cables. I just bumped the key and it fired right up.

The only aftermarket electronic device I have on there, is a PAC auxillary input adapter (2 RCA stereo inputs). I was able to log data just fine with EFI live, and my Diablo Predator never had a problem backing up or flashing the ECM with this installed, so I'm hesitant to blame it. However, if it continues to give me grief, I will remove it and give it a go.