Comment 8 for bug 619663

As you are using an intel 945 and the bug happens when you have an extended desktop with width > 2048 and there is the error message "(EE) intel(0): Failed to allocate framebuffer." this seems to be freedesktop bug 28515 (libdrm) which is fixed in:

commit 726210f87d558d558022f35bc8c839e798a19f0c
intel: Limit tiled pitches to 8192 on pre-i965.

Fixes: Bug 28515 - Failed to allocate framebuffer when exceed 2048 width
 https://bugs.freedesktop.org/show_bug.cgi?id=28515