Im sure this is going to throw a nice spanner in the works.
Im running a 6.0.1 custom ISO (the one with 9 pages of posts about it
) I have installed several of the added extras.
Im a university student so I can use both my server proxy, and I can access the university proxy too.
Using my university proxy I can access the site both through IE 6.0 and Firefox 0.8.
If I turn off the university proxy, I am not able to access the site through either.
This would certainly suggest that it has something to do with the SME proxy setup. Have you checked your squidlogs? Perhaps there is a highlight to the problem in there. Do you have squidguard installed? Perhaps the site is incorrectly listed on your blacklist.
Hope this helps
R