Vympel wrote:You have the meaning of my question ... exact.

Heh heh ...
Well, (hypothetically speaking for our US members) what you want to do is get AnyDVD HD, which is made by SlySoft in Aruba and which evades US copyright law via geography. It's also useful for watching Blu-Ray movies on a computer that lacks an HDCP connection (without it, PowerDVD balks and refuses to play Blu-Ray movies on my computer because the LCD monitor is old and does not appear to support HDCP).
Anyway, if you have AnyDVD HD, you can either rip the Blu-Ray to HD or use a UDF2.5 driver (if you can get your hands on one and it doesn't harm your system) to access the files on the disc. Once you access them, look for the huge .m2ts file; that will be the movie. Then install AVISynth and create a .avs file (let's just call it "bluray.avs") which looks like this:
Where <filename> is the filename of the huge .m2ts file. Now you can use VirtualDub to open up the bluray.avs file and scan through it looking for screenshots.
I know, it's a really unwieldy process, especially compared to simply clicking on the screenshot button in PowerDVD. What can I say; the Blu-Ray people did not want people to be able to take screenshots at all.
(Not to drag the thread off-topic, but I assume the BRD you have of Alexander is in fact Alexander Revisited - what did you think of it in comparison to the previous version(s)? I quite liked it, even though it's still ... uneven as you say).
I thought his radical re-ordering of the film improved it significantly, although he still seems too reluctant to cut excess material. There are a lot of periods where the movie really starts to drag because he thinks more is better. And of course, there are those long heart-felt talks between Alexander and Hephaiston; the less said about them, the better.