I upgraded WordPress 2.9.2 to WP 3.3.2, and qtranslate to 2.5.29.
When I activate qtranslate the whole Dashboard and Editors won't appear anymore. Only a white page!
I deactivated also all my other plugins, but still the same thing happens. I tried also older versions of qtranslate, but still I've got the same effect.
So I've got a severe problem, when I activate qtranslate, the website seems to be okey. If I deactivate it, I can finally work on the Dashboard.
Very annoying thing. I didn't found any other description of this misstake.