How to change Remaining Work in Timesheet or in Tasks (PWA 2010)

Hi,

I read in a blog (don't remember which one) that we can edit the Remaining Workin Timesheets or in Tasks only if the administrator activated the box "Only allow tasks updates via Tasks and timesheets" in theTask Settings and Display page.

I did not activate this option and this feature is still working fine. What is the "by design" truth?

NB : I'm using the Single Entry Mode.

Thanks