My theory on these sorts of problems is that movie-playing software, especially the kind that auto-runs when you insert a recorded/pressed disc. The disc spins up, Windoze identifies it as a movie, autoruns the associated player and instant BSOD (blue screen of death). Do you have a data (not movie) DVD, and if so, what happens when you insert that?
If you can remove all your player software (Sonic, WinDVD, PowerDVD, Media Player Classic etc) this might cure the problem. You can then re-install them until the problem re-ocurrs; that will at least tell you which one is causing problems. Some less drastic approaches might be:
-Un-associate DVD video files (.VOB, .IFO) with the application
-disable autorun/autoplay (in PlexTools) for your PX716SA
but they are also less likely to solve the problem.
I believe these players install decoders ("codecs") that either interfere with each other or cause DirectShow to crash because the rendering paths are corrupted.