NetMeeting 3.01 Directory Problem

We recently upgraded our desktops to XP Pro running off a Windows 2003 Server network. We had been using NetMeeting without problem until recently the Directory has started hanging. If a user clicks on the directory they get an hour glass and never brings up the directory, however if you know the user you need; it can be typed in the call box and called bypassing the directory altogether with no problem.

I tried uninstalling and re-installing NetMeeting, checking configurations, etc.....Has anybody dealt with this problem or know of a solution?