I think I fixed my issue. After reading some forum posts, I downloaded the updated file "iPhoneCalc.dll" from this link:
http://www.mediafire.com/?9ca50f9cdfcmni5

I renamed the original file "old" and copied the new one over. I've loaded several tunes with no crashes, or the program closing on it's own.

In that case you should capture it in a debug log (step 4b) and send it to support: http://www.mediamonkey.com/forum/viewtopic.php?t=69

Lowlander wrote:Try to sync a single file to the iPod Touch using iTunes. After that resume syncing in MediaMonkey as you'd normally would. Does it still happen?

Yes it still happens.

Try to sync a single file to the iPod Touch using iTunes. After that resume syncing in MediaMonkey as you'd normally would. Does it still happen?

This has happened on two XP (SP3) machines using the same iPOD Touch device. I'm able to send files to the iPOD Touch 32 gig 4th gen Firmware 5.1.1, but after a couple of dozen tunes are sent, MM closes on its own. I have it running right now and it's still open; therefore, it only happens when sending tunes to the device. I'm using MM version 4.0.6.1501. I also have the latest Apple software installed, but have it disabled from starting up. I never had this issue with my older iPOD Touch 8 gig and version 3.x of MM.