I just wanted to write that it is not reproducible but in fact it is:
It is not related to said or any video played, I've commented/ deactivated that code for now. The issue sadly seems to be a little more complex:

There is a level in my game which has caused problems for quite some time now, that is some entities do not get created successfully it seems, they are invisible and passable (but they are there, for example tested via "while(1) draw_line3d(...)" in those entities' actions). It only happens when you enter one/ some other levels prior to that.
I've thought it could be related to a damaged file but the level only uses models and textures which can be found in many other levels as well.
Then I wrote a function which writes a level protocol which sadly gives erroneous output because of engine_gettaskinfo, as discussed here: http://www.opserver.de/ubb7/ubbthreads.p...true#Post439890
(Btw. the following thread and problem probably is related: http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=445593#Post445593 )
Finally, I'm starting to think that the following issue could somehow and magically have an effect on the faulty entity creation, too: http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=439415#Post439415

When I enter said level and at least one entity is erroneously invisible, then leave, open the main menu (different level) and change the resolution the DirectX crash from my previous post appears. EDIT: The DX problem and that (solved) entity problem are unrelated.

Any help would be greatly appreciated - maybe even an inofficial interim version with those two bugs (engine_gettaskinfo + compiler) fixed? Thanks.