File Share Contents Limit (175 dirs)?

I have a file share on a Windows Vista machine that has 13k sub-directories
in it. When I access the fileshare from a Windows XP or Mac I can only see
the first 175 directories. When I acces the share from Vista as myself I see
all of the directories, but if someone else accesses it they too only see the
first 175 directories.

This seems to be a limit based on security and permissions, but I have never
heard of anything like this. Any help would be much appreciated.

Thanks,
curt