Target Groups isn't updating after moving the Computer to another Target Group

Hello,

I've a problem with my WSUS SP1 (Installed on Windows 2003 Standard SP2):

- I have several targeting groups (Laptop, Workstations etc').
- Client targeting groups are updating using the Console and not GPO
- Synchronization is occurring once a day at 22:00
- all client are reporting and by default enter into the Unassigned Group

my problem is when I'm moving a computer to any other group, it's status isn't updated and update are not synchronize by the new targeting group i moved the computer to.

in the log file on the machine I'm getting the following info:

2009-03-18          15:27:16:429       1132       10b4      Agent      * Target group: (Unassigned Computers)

2009-03-18          15:37:18:350       1132       1208       Agent      * Found 0 updates and 48 categories in search; evaluated appl. rules of 497 out of 628 deployed entities

2009-03-18          15:37:18:350       1132       bd4        AU            # 0 updates detected

2009-03-18          15:42:10:681       1132       10f0       Setup    WARNING: Self Update is in an error state

Any ideas?