Workaround: "The server is not responding" error when trying to add a contact in Groupwise Messenger

At work, our internal corporate standard IM client is Groupwise Messenger.  Today, the "Add Contact" function stopped working for me (after always having had it work fine in the past): When trying to add a new contact, the "Search Results" window would appear with its normal animated "searching..." icon, and then after 30 seconds, the search would time out with the error message "The server is not responding."  Despite the error message, I could view the online/offline status of my existing contacts with no problem (so I clearly had a working connection to the Groupwise server).

After playing with the client for a couple of minutes in an attempt to find a workaround, I did find a rather unusual workaround, somewhat to my surprise:

On the Find dialog (where you enter the name of the contact to find), tucked away in the top-right corner of the dialog is an "Advanced" button.  Clicking that button restyles the dialog with some additional "advanced" fields.  Performing the search while the Find dialog is in this Advanced mode causes the search to work correctly, and the "The server is not responding" error does not occur.

This workaround seems kind of bizarre to me -- I have no idea why it works, or what the cause of the initial issue is.  Still, I have successfully reproduced this workaround as a solution for the issue multiple times (and gone back to Basic mode in the Find dialog and had the search fail once again as it did originally), so I wanted to share the solution in hopes that it is helpful to someone.