Xati lockup

Hi,

Tried the Xati driver today, it loaded but there were about a hundred
vertical lines across the screen and then the machine locked up hard. 
Had to do a hardware reset.

The Xvesa driver usually loads fine but locks up sometime about 15
minutes into running it.

Should I try to debug somehow?  (I'll need detailed instructions.)

Thanks.
-ry

BTW,
This is a dell laptop.
lspci output follows -

01:00.0 VGA compatible controller: ATI Technologies Inc Radeon Mobility
M7 LW [Radeon Mobility 7500] (prog-if 00 [VGA])
        Subsystem: Dell Computer Corporation: Unknown device 0149
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop+
ParErr- Stepping+ SERR+ FastB2B-
        Status: Cap+ 66Mhz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort-
<TAbort- <MAbort- >SERR- <PERR-
        Latency: 32 (2000ns min), cache line size 08
        Interrupt: pin A routed to IRQ 9
        Region 0: Memory at e8000000 (32-bit, prefetchable) [size=128M]
        Region 1: I/O ports at c000 [size=256]
        Region 2: Memory at fcff0000 (32-bit, non-prefetchable)
[size=64K]
        Expansion ROM at <unassigned> [disabled] [size=128K]
        Capabilities: [58] AGP version 2.0
                Status: RQ=47 SBA+ 64bit- FW- Rate=x1,x2,x4
                Command: RQ=31 SBA+ AGP+ 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 PME-Enable- DSel=0 DScale=0 PME-