slow My Network Places but not UNC

Strange issue going on.....Over a wan link that is full T-1 MPLS if I open a
remote share from mapped drive or going to start-->run \\servername\share I
can browse files with very good speed. If I create a shortcut in my network
places that points to the same share it is VERY slow and sometimes locks up.
There are NO other shortcuts that could be causing the problem. When doing a
"start-->run" unc to open it the "window" looks exactly the same as the "my
network places" style window. What is actually different when going the My
Network Places route. Note: I have also tried setting up the shortcut as
\\192.168.1.2\share and it is still VERY slow. Servers are all windows 2003
R2, clients are all XP sp2. No firewall on any of them and the problem
happens on servers or clients. Detailed information please....