Its an IBM T40 Thinkpad:
running XP Pro sp2 , Office 2k3 with Modular Messaging client 2.0.1
The unit is connected to the LAN on which the MAS server resides.
The funny thing is, it worked fine and i made no changes to the machine, then the error appeared. I could not find any references to the problem. So i uninstalled the MM client and re-installed it...........It worked fine for another couple of weeks and then appeared again.