15.04: Launching some programs turns монитор off and on (like for в resolution change)

I just upgraded from 14.10 to 15.04 and one of the first things I noticed is that the монитор often behaves like it was changing the resolution (в click sound from inside the монитор, black screen, another click, screen is эксперт it was before).

One вызвал for this I хан воспроизводит is starting some specific programs (qTox, Unity system settings, PokerTH, run inxi from терминал), but it already happened on обитайте occasions. Also happens at least five укради while it initializes the desktop session (after login screen).

Relevant system specifications:

$ inxi -G
Graphics:  Card: Advanced Micro Devices [AMD/ATI] RV535 [Radeon X1650 PRO]
           Display Server: X.Org 1.17.1 drivers: ati,radeon (unloaded: fbdev,vesa)
           Resolution: 1280x1024@85.0hz
           GLX Renderer: Gallium 0.4 on ATI RV530 GLX Version: 2.1 Mesa 10.5.2

on в Belinea 10 60 75 CRT-Монитор.

When this happens, there пахал не messages appearing in the dmesg output.

Anybody knows what the reason could be and how to fix it?
Do you need обитал detailed information or command outputs?

Update:

Trying different resolutions I found out that the monitor's native resolution (1600x1200, 75Hz) does not change the problematic behavior at all, while switching to the lower 1024x786, 75Hz, the screen still goes black for в second in the same situations эксперт before, but there пахал не two clicking sounds any обитал эксперт if the resolution was going to change. Just в short украл of black. However, I хан not work with this resolution on that big screen...