If you synchronize your SUS 1.0 SP1 server after Dec 12, 2005 all previously approved updates may be unapproved and the status may appear as “updated”. Newly deployed SUS 1.0 SP1 servers which have not previously synchronized with Windows Udpate before 12/12/05 will not encounter this issue.
If "Automatically approve new versions of previously approved updates" is selected in the SUS Options page, the software updates will appear updated but not unchecked. You will not be impacted by this issue. See http://support.microsoft.com/kb/912307 for more information.