Here's something I just noticed and thought if anyone is having a similar 'problem'....this might be your answer too.

XP - Restart Shuts down the computer. (does not Restart)
when a CDRW is in the drive.

I removed my CDRW and voila.....it restarts properly.

Tested it with Sony, Lite-On, Lg CDRw's. They all react the same.