connection problems to the server

Need your help.

When I load frontpage 2002, my default web site show up
(www.cekurnet.com) and ask me for the username/password).
I can open any page on my site without any problems, make
change and save it without any problems,but when i try to
SAVE AS a page or save a new page i got that message error:

Documents in this folder are not available. The folder may
have to been moved or deleted, or network problems may be
preventing a connection to the server

I open My Network Places and try to open directly from
there and got the same message error.

I try different web site that i own with diffrent web
hosting company and got the same error.

I run under Windows 2k with all the update install.

Thanks for helping and sorry for my bad english.