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AMD Radeon HD 7790OC Second Monitor not detected

Hey,
I'm having problems with my second monitor with the following GPU:
AMD Radeon HD 7790 OC(using the FOSS driver)
While having both monitors connected, my xrandr output only shows the first:

Code:

xrandr: Failed to get size of gamma for output default

Screen 0: minimum 640 x 480, current 1920 x 1080, maximum 1920 x 1080

default connected 1920x1080+0+0 0mm x 0mm

  1920x1080      0.0* 

  1280x1024      0.0  

  1440x900        0.0  

  1280x960        0.0  

  1024x768        0.0  

  800x600        0.0  

  640x480        0.0

The second monitor can be detected using the proprietary driver, but it is really bug and, of course, proprietary.
Is there any way that I can get dual monitor setup to work with the free driver? I couldn't find anyone else having this problem with this particular GPU.(I'm assuming there is a lot of difference with this GPU's drivers compared to the other Radeon ones, since the proprietary driver is the only one not listed as "nXXX Series" but as "7790" in particular(see AMD site)).

What happens when you explicitly activate the second monitor in your xorg.conf file?

Only the first monitor displays something, but nothing usable.
I couldn't find anything usable in the X log either:
http://pastebin.com/Ryjui7rc

What exactly is happening if you used the proprietary driver? I've had some difficulties with the proprietary driver trying to get it to work, but once I've figured it out, it had been a wonderful experience for me.

My setup is a two radeon cards for 3 monitors. Crunchbang, Lubuntu and Bodhi (the newest one and will be experimenting soon). So far Crunchbang and Lubuntu had been working with no issue for 4 months now since it worked.

Its behaviour after a reboot seems unpredictable, sometimes it stretches the picture weirdly and so on.
But, as I said, I rather work with only one screen than with the proprietary driver.
Its just that this is something that should work with the free driver(according to its documentation) but it doesn't for me.

do you have a xorg.conf file on your /etc/X11 folder? Can you post it?