Hiya,
I'll try to be as clear as I can with this one but please bear with me if I get fuzzy / obvious misunderstandings as I'm just getting into Drupal & am more pedagogy than technology... at my peril!
I've had this problem with other sites (for example Guardian Unlimited, Blogger, parts of my Wordpress web-based backend) through my universities proxy server. Basically when you visit the site you do not get the most recent version, only the latest bit someones used... and often a few versions before that. So with the Guardian you get Wednesdays news on a Friday & have to refresh manually, and with my instillation of Drupal I get old versions / themes which I moved on from week ago.. and have to refresh every second page.
Here's the site: http://incsub.org/association/
Now, some things have no problem, the BBC is fine, and my Wordpress blog ( http://incsub.org/blog) is fine.
I don't know if this is because they don't allow the proxy server to cache them, or because they are running out of particular databases or what.
The one thing I do know is that IT at teh Uni aren't going to help and that as long as this remains the case the plans I've got for implementing Drupal in courses across faculties (and they're big plans...) are going to be totally shot through.
Any help at all or pointers to where I might be able to find some or perhaps just telling me I ought to just give up because there's nothing I can do... would be much appreciated indeed!