Hi (you used my multi-layered PDF).
I'd remove the processor (take care not to bend the pins).
Check the contacts on the IC socket for short circuits - normally (but not exclusively) adjacent pins by using an Ohm Meter.
Re-attach the battery(s) and power up still without the IC. Check nothing gets hot including the regulator.
If you have a meter then check the correct voltages are present at the correct pins on the IC socket.
Once you are happy- turn off and (after a few minutes) plug in the IC again.
May be too late by now - but check out my tutorial at http://www.societyofrobots.com/member_tutorials/node/190
(Particularly Section 3) for your next build. The circuit may be different but the principals apply.