OS X Mountain Lion - Kernel Panic and Restart after Sleep
Solution 1:
If you want to determine whether your panic is caused by hardware or software problems, I recommend you to install Mac OS 10 on a USB stick, it needs to be at least 8 GB. Boot up from it. Now try sleeping. If it's ok, its most likely (99%) a software problem. It may also be your HDD, which is highly unlikely.