Comment 21 for bug 586243

I've been getting this same issue starting about a week ago (~Oct. 1 2011) on Ubuntu 11.04 with Unity. I can't remember it occurring any other time except when I have Gnome Terminal maximized (which has often been the case recently), and it seems to happen about every few hours.

$ uname -a
Linux 2.6.38-11-generic #50-Ubuntu SMP Mon Sep 12 21:18:14 UTC 2011 i686 i686 i386 GNU/Linux

$ sudo lspci -vvvv -s 01:00
01:00.0 VGA compatible controller: ATI Technologies Inc RV350 [Mobility Radeon 9600 M10] (prog-if 00 [VGA controller])
 Subsystem: Hewlett-Packard Company Device 08a8
 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
 Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 64 (2000ns min), Cache Line Size: 64 bytes
 Interrupt: pin A routed to IRQ 10
 Region 0: Memory at 98000000 (32-bit, prefetchable) [size=128M]
 Region 1: I/O ports at 2000 [size=256]
 Region 2: Memory at 90400000 (32-bit, non-prefetchable) [size=64K]
 [virtual] Expansion ROM at 90420000 [disabled] [size=128K]
 Capabilities: [58] AGP version 2.0
  Status: RQ=80 Iso- ArqSz=0 Cal=0 SBA+ ITACoh- GART64- HTrans- 64bit- FW+ AGP3- Rate=x1,x2,x4
  Command: RQ=32 ArqSz=0 Cal=0 SBA+ AGP+ GART64- 64bit- FW- Rate=x4
 Capabilities: [50] Power Management version 2
  Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
  Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
 Kernel driver in use: radeon
 Kernel modules: radeon, radeonfb