Actual Duration Not Calculating Accurately

I am running MSP 2007 (not server), and am trying to get the actual duration to display the correct value. As an example, I have inputted an "Actual Start" date of Sep 1st, with a Project Status Date of Sep 5th, and remaining duration of 5d. Based on this information, when I update the progress (Tools, Tracking, Update Project, Ticking Option to Reschedule Uncompleted Work To After Sep 5th), I should see Actual Duration of 3d (Wed, Thurs, Fri), and an early finish date of Sept 10th. While the task early finish date is accurate, the actual duration is showing 0d.
Note I am using Physical % complete.

I think that the MS office installed in your computer is corrupted and for that reason you are getting that problem. My suggestion to you is to uninstall that from your computer and then install that over again. I am not very sure that it will resolve the issue for you but if you are not able to resolve the problem then there are some chances that it will let you out of the issue. Good Luck!!!