Trying to remove a machine from the selection list

I'm trying to remove a machine from the selection list.  The machine was converted to VMWare and renamed.  The physical machine was also renamed.  We basically segmented the one machines duties into two.

So when I try to remove it from the selection list, Symantec Backup Exec 12.5 keeps prompting me for an administrative account for the machine.  I'm not trying to go on it, I need to uncheck it.  I right click and select Uncheck and the selection does not go away.

I need to remove this machine because it's causing failed backup jobs as it can't attach to that machine.  It looks like maybe our other servers in that job are backing up, but still I don't like to see a lot of red in the job history.

Thanks.