I’ve also seen some strange behavior in Project 2010 on a fixed work Task.
I create a Task and define (in this order) Work of 12 hours and Duration of four days I then add two Resources without specifying a percentage. They get added at 38% each, and the Duration (as expected) gets cut in half.
I correct the Duration, and when I tab out if the column I get the little green triangle prompt. From the warning menu I make sure I’ve selected to change the hours the resources will work.
This should trigger a recalculation of the Resource allocations, but that doesn’t happen. The Work and Duration values are correct, (12h and 4d) but the Resources each still show a 38% allocation.
I have to artificially bump the Work value up and down to trigger recalculations of the Resource allocation percents to get the correct 19% for each Resource.
Since we’re implementing Project Server and expect it to provide accurate Resource allocation information, the above failure to update an allocation is troubling.