I've been using Fedora 15 for a couple months now and haven't had any problems. Last week I switched desks and got a new monitor, and now all of a sudden it will randomly freeze up.Also sometimes without freezing it will make all title bars (including the system bar at the top of the screen) and system images (such as the images for the launcher on the left side of gnome 3) plain blue, and any text on them is just blocked out in darker blue.It usually freezes some time after everything turns blue. I can switch to another terminal using Ctrl + Alt + F2 and reboot. I checked the messages log and found this:kernel: [ 1706.856599] [drm] nouveau 0000:01:00.0: PGRAPH - TRAPkernel: [ 1706.856602] [drm] nouveau 0000:01:00.0: PGRAPH - ch 4 (0x0000b45000) subc 5 class 0x8297 mthd 0x0e08 data 0x04380000kernel: [ 1706.856611] [drm] nouveau 0000:01:00.0: VM: trapped read at 0x20ff202000 on ch 4 [0x00000b45] PGRAPH/TEXTURE/00 reason: PT_NOT_PRESENTkernel: [ 1706.856695] [drm] nouveau 0000:01:00.0: magic set 0:kernel: [ 1706.856698] [drm] nouveau 0000:01:00.0:  0x00408904: 0x8008700fkernel: [ 1706.856700] [drm] nouveau 0000:01:00.0:  0x00408908: 0x20ff2020kernel: [ 1706.856702] [drm] nouveau 0000:01:00.0:  0x0040890c: 0x40000e04kernel: [ 1706.856703] [drm] nouveau 0000:01:00.0:  0x00408910: 0x20200000kernel: [ 1706.856705] [drm] nouveau 0000:01:00.0: PGRAPH - TRAP_TEXTURE - TP0: Unhandled ustatus 0x00000003kernel: [ 1706.856707] [drm] nouveau 0000:01:00.0: PGRAPH - TRAPkernel: [ 1706.856709] [drm] nouveau 0000:01:00.0: PGRAPH - ch 4 (0x0000b45000) subc 5 class 0x8297 mthd 0x1b0c data 0x1000f010kernel: [ 1706.856716] [drm] nouveau 0000:01:00.0: VM: trapped read at 0x20ff202000 on ch 4 [0x00000b45] PGRAPH/TEXTURE/00 reason: PT_NOT_PRESENTMy system admin thought it might be some loose RAM, but I tried taking out and putting back in all my RAM sticks and it didn't work.I am using a graphics card that I took off an old machine, under Fedora System Settings it says my graphics driver is: Gallium 0.4 on NV86.  Is it time to upgrade to a new graphics card? If so it's not a big deal, I can get one that will fit my needs for around $50. I'm just not sure if that's the problem, or if it can be fixed with a different way.
System freezing on Fedora 15 - graphics issue?
fedora;desktop;freeze
It may be the nouveau driver, which many people advise to void like the plague. This link explains how to disable it and replace it with the native nVidia drivers.