I have an issue with desktop effects. When I try to enable them, it is OK for about 5 sec, after that the effects are disabled.
When I logout and login again, the desktop effects are enabled. But after some time (for instance, 3-5 min) they are disabled automatically again.
I use OpenSUSE 11.2:
01:00.0 VGA compatible controller: nVidia Corporation G73 [GeForce 7600 GS] (rev a2) (prog-if 00 [VGA controller])
Subsystem: Micro-Star International Co., Ltd. Device 0640
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: 248 (1250ns min, 250ns max)
Interrupt: pin A routed to IRQ 16
Region 0: Memory at e4000000 (32-bit, non-prefetchable) [size=16M]
Region 1: Memory at d0000000 (32-bit, prefetchable) [size=256M]
Region 2: Memory at e5000000 (32-bit, non-prefetchable) [size=16M]
[virtual] Expansion ROM at e6000000 [disabled] [size=128K]
Capabilities: [60] 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-
Capabilities: [44] AGP version 3.0
Status: RQ=256 Iso- ArqSz=0 Cal=3 SBA+ ITACoh- GART64- HTrans- 64bit- FW+ AGP3+ Rate=x4,x8
Command: RQ=32 ArqSz=2 Cal=0 SBA+ AGP+ GART64- 64bit- FW- Rate=x8
Kernel driver in use: nvidia
The driver for video card is installed.

There are no messages about video card problems or system requirements. Could you please provide any info, what can I do to prevent automatic effects disabling?