explorer hangs on network

strange problem
XP pro causes explorer to not respond when moving through
a network. If I type in the address (eg.
\\bigrig\files\ted) it will work, but if I just type
\\bigrig and then try and open the \files directory,
explorer hangs. Another thing that works is if I "Add
Network Place" and select "Open this network place when I
click finish". After that, though, the link in "My network
places" will cause explorer to hang.

Internet works fine. This is a mixed XP Pro, Win2k, 98
network. Other XP boxes work, but they were upgraded to
XP from 2k. This problem is repeatable on machines that
have fresh XP installs with the defaults and nothing
else. It recieves an IP fine, you can access a share on
the machine fine, the problem is seeing out.

any hints?
-ted