Guys,
Here's my experience with connection problems.
I had loads of problems connecting to II shortly after the forum was upgraded. Interestingly, II was the only website I could no longer connect to.
I came to the conclusion that changing browsers didn't make much difference. IE8 works fine with II and I'm using it now.
All proxy servers I found to be too slow and a lot display ads. which are annoying. Some of them could connect to II and some still couldn't.
I tried all sorts of tricks to connect (deleting caches, updating stuff etc.) and I believe that the problem was down to the dynamic IP addresses allocated by my ISP.
After looking at several tracert logs, I could see that my connection with IP addresses from a certain range were being dropped at a server in the US shortly before reaching the II server.
Rebooting my router allocated a different IP address, though because it was from a similar range of numbers my connection was still getting bounced.
As it happens, my ISP at that time was in the process of moving accounts to a parent company. That move meant that my dynamically allocated ISP range would be different, and lo and behold as soon as the move took place, my connection to II was again flawless.
It seems that some servers along the route to a website are more sensitive to IP ranges than others and these ranges can get labelled as undesirable if in the past one or two of the IP addresses from the range have been used by spammers.