I just fixed a strange problem. All of a sudden overlay mode stopped working when I watched movies. I checked my Dxdiag settings (Start>run>dxdiag) and DirectDraw acceleration and AGP texture acceleration was unavailable.
I reinstalled DirectX and the drivers for my Graphics card. To no avail.
Then in a forum I found the solution:
1. Start netmeeting (start menu>run, type conf.exe in the run box and hit enter)
2. Go to tools and enable remote desktop sharing, install with the wizard.
3. After the wizard finishes go to tools again and uncheck remote desktop sharing.
4. Close Netmeeting.
5. Run Dxdiag (start>run type: dxdiag), AGP texture acceleration and DirectDraw acceleration should be available now! 🙂