Hi Chris,
Looks like your files are 16-bit signed integer from the BSCALE/BZERO values. Try the settings I suggested here and see if they help with your existing data:
http://pixinsight.com/forum/index.php?topic=7445.0
If not, I'd be happy to take a look at some of your files early next week (I hope to be imaging this weekend!) and see if I can figure out what is going wrong.
Cheers,
Rick.