The IE crash I think is an IE problem. I've been using this successfully with Netscape and or FF, without any problem, and I don't notice it to be having any adverse affects on my bandwith. I've basically told my users to switch to a mozilla based browser; we've been having problems with AJAX as well.
If you really need to stick to IE, you might want to make sure of the folloowing. They've helped a bit with mine:
Make sure that you don't use domain.com in any of your links; use
www.domain.com.
Turn AJAX completely off.
It's helped for us, if you really need to stick with IE.