No Windows XP Inventory

Hello,

we are running several XP and 2K boxes.
The 2k boxes are completly in the database and listed in reports.
The XP boxes are created as workstation objects and the "Minimal Inventory Data" are
avaiable.
But the complete inventory is not avaiable. I reinstalled the agent on one computer and
this box now also have an full inventory.
But in a report no Windows XP boxes are listed. There is also no possiblity to select WXP.
Only, NT, ME, 2000 95/98.