I have 15 machines on the LAN, one of which is running Vista Home Premium 64
bit. The server is Windows Server 2003

When browsing photos (.jpgs) on a network share all of the machines are
lightning fast to display the image on the double click then quickly flip
through the photos one after the others using the arrow keys except for the
fastest machine of all that takes about 15 seconds to open the file then 3-5
seconds to flip through each one.

It does not matter which photo viewer I am using (I've tried about a half
dozen of them) and other documents from the shared folder (.doc, .xls, etc)
are not slow to open.

I've tried 2-3 different antivirus programs and even disabled the AV
entirely with no success.

Does anybody have a fix for this?