mo62987:
Man, left town for a couple days and come back to lots of good info here... thanks for the input!All the "It's the relays" comments had me second guessing everything, so I had a look back into the code. Looks like I never brought the relay coils back LOW again after they latched. There's a good chance it has something to do with that. Unfortunately, I'm having other issues with just uploading a sketch all of a sudden. So I won't be able to test the theory until I get that sorted out. If that doesn't end up solving the problem, I'll follow up with all the documents. Thanks for the help.
If I remember correctly (been on multiple threads, so tend to get them confused :P), you have no diode protection on your relays? If so, consider that a possible source of your strange behavior.