Problems with Workgroup e-mailed update

Using the "Workgroup" facility to get the project update from my team colleagues I obtain problems.

The situation is:

When I receive a TeamStatus Replay with the hours registered on it and pressed "Update Project", the original work is increased instead.

For example, If I had this schedule:
Mon Tue Wed
Work 4h 4h 4h
Actual work

and this TeamStatus replay info from a colleague:
Mon Tue Wed
Actual work 2h 1h

when I press "Project update" occurs this:
Mon Tue Wed Thu Fri
Work 2h 1h 4h 4h 4h
Actual work 2h 1h

instead this (manual update)
Mon Tue Wed Thu Fri
Work 2h 1h 4h 4h 1h
Actual work 2h 1h

Somebody knows what ishappening?

Thanks,