PM override of task status

We are just starting to use MS Project 07 Pro on PWA. The PM would like to
enter updated task status from tasks that are in the schedule and have been
completed (as opposed to getting the task owners to update the task).

Is there a way that a PM can enter task progress information? I know this is
counter to the general idea of using Project Server - however - with a new
project and process, I'd like the PM to get the project up to date before we
start asking for task updates from team members. Whenever the PM updates the
tasks, a message comes up that says that the sync will cause all changes to
be lost. There doesn't seem to be an option for the PM to override the sync.

Thanks!
--
-Celeste