Asset Auto Assign Workstations

I have possibly been confused over the Auto Assign Workstation function as I thought it had worked.
However On the Asset page it is stating 166 Unassigned Workstations.

I choose Auto Assign and have list brought up in 50's and assign them.
I get teh green progress bar advising it has assigned them, and a green notification status at the top of teh page, advising it has been done.
The list however doesn't change, so I move over teh page to the next 50 and repeat the exercise.

Once complete I come out of the screen.

However it is still showing as 166 unassigned workstations.

Any suggestions as to what I am doing wrong or changes need to make it work.
Kind Regards,

Andy Fox

Version 7
Build 7002
SQL Server
IE 6