OK, check the event log of the WDM PC and see if there are any errors on ftp access or exceeding the 10 user limit. Open WDM and right click on the Master Repository and select test – did that all work?
On the WTOS device have a look at the system log and see where the device was trying to get to:
myserverip/office or whatever
I am assuming here you have the enterprise version of WDM?
Also jokes aside, you really should run enterprise on a Windows Server OS. I would recomend download ing VMware server (its free) at a minimum and running it there if you want to save on hardware. At least you can back it up and and dont have to worry about the PC crashing again. Secondly XP pro only supports 10 connections and this oftern causes problems when clients try to get the config.
Finally as a matter of interest, if you G-Key a client to remove all prior settings does it work correctly with the new WDM server.
Cheers,
-TT