Ok...looking further into my problem with Magento hanging on upload I think I may have found the reason.
I keep my DB in a master XLS sheet and then copy out to a new CSV file and save it so I can upload. I just noticed that when going from XLS to CSV my category numbers are getting all funky which is probably causing magento to bomb out.
[screen shot after opening saved CSV is below as well notice it circled in yellow]
I’ve tried formating the cells every way I can think of. I’ve tried copying them out to Notepad and then back into the CSV but I’m not getting anywhere.
Click thumbnail to see full-size image