NW4.91Sp2 client on the XP_proof_Sp2

If local user log in to XP as a memeber LocalAdminGroup -
Update Agent from the NW4.91.sp2 work Greate.

If local user log in to XP as a memeber LoaclUserGroup -
Update Agent from the NW4.91.sp2 not work. !!

Any body Help me !

Serg