Running Windows 7 Home Premium 64-bit. I have two Pioneer DVD/CD ROM drives installed, identical models (DVR-215). Not sure when this happened or what caused it:-

I noticed my number one drive was not auto starting a DVD when inserted. Went to [b:aucnzit2]Properties>DVD Region[/b:aucnzit2] (tab) and saw it was set to Region 2 (should be Region 4). No idea how it changed all by itself?

It is showing 4 changes left, so I select the new region (4) and click [b:aucnzit2]OK[/b:aucnzit2], then click [b:aucnzit2]OK [/b:aucnzit2]again to confirm and I get this error message:
[attachment=0:aucnzit2]DVD Region error.png[/attachment:aucnzit2]

So I obey orders (as always) and insert a Region 4 DVD, wait until it has finished reading and then try again.....same result.
[i:aucnzit2](NOTE: Drive number two is fine with all correct settings retained)[/i:aucnzit2].

Plenty of reports of this issue around the net but, as usual, zero solutions...not any good/helpful ideas either.

Please do not tell me to install VLC, I already have that installed and know how to 'get around' this issue, what I am looking for is a reason why and a proper fix?

Another Win7 bug maybe??

TIA.....Jim