I have tried that and the only thing that seems to consistently work is having to uncheck autofit window, and recheck it. Not very 'auto' if you ask me.
I have read another topic that said to check the "auto-detect video settings" box under the VMs video card.
All of my VMs are Win2k3 R2, and each has a different desktop resolution. It doesn't seem to matter what resolution I set it at, as the auto-fit not working is a random occurrence.