I don't get Quicktime to run under LC 6.7.6

[Tiemo Hollmann TB]

Hello,

OSX 10.9.5. Because of video file compatibility I still want to use QT in
6.7.6. In preopenstack I set:

set the dontuseQT to false

put the qtVersion into tTest

In IDE:  start player "myplayer" -- nothing happens. The player runs (I get
the playStopped status after the video is finished), but doesn't shows any
video. Doing "set the dontuseQT to false" multiple times again, changes
nothing.

When closing the stack, removing from memory and reloading the same stack a
second time, everything works fine like before in LC 6.5.2, the videos are
played fine. So it seems, it has something to do with loading and providing
QT. The first opening of my stack seems to load QT, but doesn't provides it
to my stack. When opening the stack a second time, it now catches the
properly loaded QT.

In a standalone the videos are not played anymore at all.

Does anybody got QT to run under 6.7.6? Any ideas, what else I could do?

Thanks for any hints

Tiemo