I have some problems involving a Macbook Pro Mid 2009 13" (MacBookPro5,5) running a Debian 7,7 Whezzy and a LCD screen Benq E2200HD.
I am using a Mini DisplayPort to VGA adapter in order to use the screen with the port provided by Apple. The problem is located in the screen resolution and it is software related.
The screen flickers at high resolutions and the flickering rate descends with lower resolutions, this seems to be software related because it only happens when an application is running in foreground but when no applications are being showed in the screen and just the Gnome3 desktop is running (even being the main X screen) it doesn't.
The flickering happens continuously in the highest resolution available (1920x1080) but it doesn't seem to be related with the GPU (Nvidia GeForce 9400M).
It seem software related and if possible I want the highest resolution available 1920x1080, right now I'm using the screen at 1440x900 and the flickering happens... sometimes, it is impossible to stablish a determined period, it seems random.