I had similar problems with IE6 and one point is that it is hard to uninstall - as I recall - and though I also got help from Microsoft tech it wasn't until I had explored the tech articles in the knowledge base that I eventually succeeded.

It was a while ago, so I can't recall enough detail to help directly.

I will ask if you are running Norton Internet Security, because I was and a corrupt file in it was compromising connectivity.

This may be irrelevant to you, but since I gave up, in disgust, with Norton (Symantec) for want of any meaningful assistance, and switched to McAfee I have never had connectivity problems of any sort, except of course with bad stuff which McAfee (and Ad-Aware and Spybot) block.

Good luck.