I cannot access the backend of my company's website from the computers at work. We are using IE 7 on Windows XP. We had problems viewing the entire site initially due to a problem with the internet provider. They eventually fixed the problem, but now I can't seem to log in to the CMS. It worked a couple times, but I typically get an error after sign in and can't access the page.

I though it may be a glitch with the site, but I have tried logging in on numerous computers with different operating systems, internet providers and browsers and was able to do so successfully.

I am no IT pro, and I can't think what could be the problem unless there is an issue with our firewall or another issue with our internet provider.

Any suggestions on things I can try before spending years on the phone with the provider?

Does the login system use an obscure port that is being blocked? If you are using active scripting, IE7 likes to block it. Check the security settings and see if there is something wrong there.