GMail connection issue
We seem to have a rather odd firewall / filtering / goodness-knows-what issue affecting GMail. Users can get to GMail's login page, but no further - after clicking "login", the browser just stays on a blank page entitled "redirecting...". We have a Firebox firewall appliance, which seems to be working just fine - it's set up with a bunch of port-forwading rules and filtering policies (the filtering policy processing is handled by a separate server), and as far as I can make out there's no rule anywhere in there that should be blocking anything to do with GMail. If it was, we'd see block messages in the log file, which we aren't.
We have some other odd problems with som other websites, YouTube in particular - some computers were simply refusing to load YouTube, despite it not being blocked by the Firewall. To fix this, it turns out we needd to delete and re-create the users' profile, which is just plain weird. However, that doesn't seem to fix this GMail issue, so I'm inclined to think this is a different problem.
Anyone any experience with GMail network settings? I've never had an issue with it before, it's always just worked. Is it a firewall issue or something to do with the clients again?