System:
SUSE 12.3 in a WINServer2008 enviroment: This thread is valid for all SUSE - WIN applications.

You might face the same user can access Winserver from one PC and not from another PC.
This problem might happen when upgrade from one release to another.
(and SUSE will not be able to solve it :-) )
The problem is known for WIN too, not only SUSE

Solve:
delete the user on the PC your Laptop. (Best is a second user as well)
reboot
install the user again.
Problem is solved.