Played BD for ~10 hours with no further NAV problems after second reinstall. Then this morning, started BD and during introductory video, the NAV internal error screen popped up. I immediately quit BD and checked NAV - got the "NAV has been tampered" message. Rebooted my system and suddenly NAV was OK again. Got the Sasser fix program from Symantec but it did not detect the presence of worm. Restarted BD and played for about 3 hours with no problems. This is one wacky bug and can't get it to recur predictably so it can be reported to Symantec. AEEEEEE!
