Problems with Video/Movie


I´ve very strange Probs while trying to work with Quicktime movie.
(Mac OSX 10.6.8, MacPro 2x2.26GHz Quad Intel Xeon, Cubase Artist 6.0.5).

The first try to import a movie ends generely with a freeze of Cubase - nothing helps.
I tried 2 different kompressors, Sorensen3 and H264… - both don´t work!

Then I load a new, emty project, and switched off “extract audio from video” inside Cubase setup, and suddenly it works. (btw - there are no audio in my movie)
Then I start my actual project and now I could import the video, and it works for this session perfect!

But after closing Cubase and reopen my newer saved session - again nothing works.
No playback, no video scrolling - only hanging Cubase.
And the test to delete the video, ends in complete freezed Cubase.

I´ve no idea whats wrong.
Make I a mistake??
Or are there probs with 6.0.5 and movies???

Please help.
(btw, I started this thread in the german section too)

Thanks, Jörg

it has nothing to do with my project!
after importing a video into an emty project…
saving - closing and restarting it…
Cubase is freezed - nothing helps