This is weird. I'm using 12.04 on an emachines e443 64 bit computer. When I open a photo in Gimp 2.6.12 and I click to draw a rectangular selection area it instantly shows a black screen with some logging out text. Immediately afterwards my password screen for logging in on the computer appears. There is no error message, just an instant and direct logout.
In the name of science I repeated the situation, and was able to read something about "Start ClamAV" in the black screen. It goes so fast I can't read all of it.
Since I also have a windows partition I know the computer isn't doing a complete restart or I would have the option of selecting either OS. Any thoughts?
My processor is:
AMD C-Series dual-core processor C-50 (1.0 GHz, 1 MB L2 cache, DDR3 1066 MHz, 9 W)
My graphics card is:
AMD Radeon™ HD 6250 Graphics with 256 MB of dedicated system memory, supporting Unified Video Decoder 3 (UVD3), OpenCL® 1.1, OpenGL® 3.1, OpenEXR High Dynamic-Range (HDR) technology, Shader Model 5.0, Microsoft® DirectX® 11
When I was trying to make the computer a bit less sluggish in Windows, before installing Ubuntu, I threw 8GB of RAM on it, so I know this isn't a lack of memory issue.
I used 12.04 for a while with Gimp and had no issues. This started sometime between July 4th and now. Perhaps a recent update caused the problem... ???
/var/log/Xorg.0.log,/var/log/Xorg.0.log.old, as well as.xsession-errorsand.xsession-errors.oldfrom your home directory, to the bug report. (You may even be able to gain some insight into what's going on by reading those logs yourself.) – Eliah Kagan Jul 14 '12 at 15:57