Save As... causes XP MSOffice 2003/2007 Applications to hang

Basically anytime a user on my internal network has an MSOffice application open on a Windows XP machine and does anything that would open a File dialog (i.e. Save As..., Open..., etc.), it causes the program to hang indefinitely and the user ends up losing their work. Anyone have any experience as to what might be causing this? Any advice on how to go about determining why it is happening? How to fix it?

From serverfault vicatcu

• Typically that's due to a network share that's not responding in a timely fashion. Have you recently decommissioned a common network drive or printer or some other share? Try it on a machine that has no share connections (that is, a net use from a command prompt shows no entries in the list).

  I've seen badly configured antivirus clients do this as well, where they're configured to scan network shares.

  I've also seen evil Explorer shell extensions (like TreeSize's extension) cause this, where the extension hits network shares and tries to do something like index the entire share.

  From squillman