Well, there's no confusion really...
There are 3 different BDR-206 models:
The first two only differ in firmware, the hardware is the same.
The last one is based on entirely different hardware and obviously the firmware is different too.
Therefore, the exact drive you'll get (BDR-206xBK) depends on that x. If the x is missing it is a BDR-206, otherwise it is either a BDR-206D if x=D or BDR-206M if x=M. The BK ending is irrelevant. Most of the drives sold in Europe seem to be BDR-206D ones at this stage, with some stores selling the BDR-206M model as well (at a higher price tag than the D version).
You should update the drive with the firmware meant for that model.... if its a D model use a D model firmware, etc ...
Yes there was a bit of an issue with Pioneer initially releasing the wrong firmware for the BDR-206D, but that has been sorted out now. Everyone makes mistakes now and then ... but at least Pioneer was quick to sort it out ...
Nobody else reported the issue Zibi00 had, so his problem seems to be an isolated one rather than a widespread one. It might well be somehow related with his mobo/chipset/controller/drive/BIOS/settings combination.
In terms of firmware update sources these 3 links are a good start:
I would advise against buying a Plextor PX-B940SA BDR-205 rebadge, because they haven't released a firmware update in ages (still stuck at version 1.08) and you can't flash it with the much newer 'standard' 1.11 Pioneer BDR-205 firmware at this stage (there's no kernel firmware available to do so). Pioneer released 3 firmwares since the Plextor 1.08 one, so better buy a proper BDR-205 if you can find one.