SW 2012 Part Crashes

I made a simple gear in SW2012 SP4 yesterday that used a couple equations to help size the gear and control it's tooth profile. I sent it to another person also using SW2012SP4 and he was unable to open the part. His instance of SW would hang and crash.

I checked the part this morning and it worked fine for me, so I resent the file to him, and that didn't help. I just checked about 1 hour ago and now the file doesn't work for me either. The file last modified date is still yesterday, so nothing should have changed.

How can I go about figuring out what is wrong with this? There are no debug messages appearing, and this "error" has me scared for other parts. The part in question is attached.

SolidworksParts And Features