The client could not connec to the remote computer

I used to be able to connec to remote Windows computers without any
problem, up until I ran a bunch of software updates. At least I think
that's what caused the problem. At any rate, whenever I try to connect
to a remote computer, I get the following error message:

Either remote connections are not enabled, the maximum number of
connections was exceeded, or a network error occured. Try connecting
again later or contact your administrator.

I know the problem is localized to my machine, because all of my
co-workers can connect to the same remote Windows box without any
error messages. I've tried looking at all my Sharing and Network
preferences, turning off Firewall, and all the usual stuff, but
nothing works. I've even deleted all my preferences and created a new
user, but none of these solutions worked.

This seems to be a fairly common problem with RDC and Panther. I've
seen several posts on this forum, but I have yet to see a fix. I'm
hoping when Apple releases 10.3.3 soon that it solves the problem. But
if it doesn't, does anyone know of a fix?

Thanks in advance.