cannot download files when logged into server.

[ClareSnyder]

I have 2 Del desktop computers running WinXP Pro. They connect to the internet through a Cisco 1600 Router and DSL.
When logged on locally, there are no internet problems.
We are implementing roaming profiles, and server authentication for privacy reasons- and now, when logged in to the network, we cannot download files from the internet. In particular, if we go to a website that has documentation files (that can be easily downloaded when logged in locally) the brouser comes back saying it cannot download file XXXXX from server YYYYY. It then says the page is not available.
Log in locally, and it downloads without a problem.

What causes this, and how do I fix it?

 

[claresnyder1]

A few more details - if the user has administrator or supervisor access, there is no problem downloading files. Superuser cannot download files. Not a good idea to have all users supervisors or administrators.

Any ideas?? I'm stumped, and spent over 4 hours on the phone waiting for Microsoft tech support - and I'm paying for the call and the support!! Never got an answer - from noon to quitting time.