My dual monitor settings worked perfectly fine until just recently. Now the resolution on the second monitor is very low and it shows white vertical stripes. I am using Ubuntu 12.04 with GNOME 3.4.
I am using a docking station for my Thinkpad T410s, that is how the Laptop is connected. The main monitor (which works well) is connected via DVI. The laptop monitor works well wenn not attached to the dual screen system. If I turn off the main monitor via software, the laptop monitor still shows white stripes.

Here is my xrandr -q:

  Screen 0: minimum 320 x 200, current 3360 x 1080, maximum 8192 x 8192

  LVDS1 connected 1440x900+1920+0 (normal left inverted right x axis y axis) 304mm x 190mm

   1440x900       60.1*+   59.9     49.3  

   1360x768       59.8     60.0  

   1152x864       60.0  

   1024x768       60.0  

   800x600        60.3     56.2  

   640x480        59.9  

VGA1 disconnected (normal left inverted right x axis y axis)

HDMI1 disconnected (normal left inverted right x axis y axis)

DP1 disconnected (normal left inverted right x axis y axis)

HDMI2 disconnected (normal left inverted right x axis y axis)

HDMI3 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 509mm x 286mm

   1920x1080      60.0*+

   1280x1024      75.0     60.0  

   1152x864       75.0  

   1024x768       75.1     60.0  

   800x600        75.0     60.3  

   640x480        75.0     60.0  

   720x400        70.1  

DP2 disconnected (normal left inverted right x axis y axis)

DP3 disconnected (normal left inverted right x axis y axis)