Pioneer 106 DVD drive plays some DVDs, but not others! (not a problem of regions)

Hi,

Up till recently, I've only played ONE "all region enabled" DVD on my Pioneer 106 DVD drive. Up till then, no other DVD was played in the drive, nor did I upgrade the firm-ware/flashed it to make it region free etc. The drive's the way it came. The s/w I used to use to view that DVD was WinDVD 2.x(?)

Last week, I got another DVD, a Region 1, and I upgraded to WinDVD 4.0. The Region 1 DVD plays without problem, but the all region enabled one doesn't anymore! WinDVD crashes when I load it (causes an error with some .dll file) and PowerDVD says the disc is dirty or unreadable. I dont think that's the case as I've not loaned the disc out to anyone, it's always stored in its case and a physical inspection of the disc shows no serious scratches etc. Viewing the contents of the DVD in Windows Explorer isn't a problem either - i can see the directories and files.

The drive is installed as a master on the secondary IDE port, a configuration which worked till recently. WinME's my OS.

Anyone know what's up? Did playing the Region 1 DVD lock my drive or something?

thanks!

 

anyone?