I have a dual monitor config on my 1st generation Mac Pro.

I have only had one problem - my menu bar icons disappeared a day or two after the update, and I had to restart to reinstate them. It hasn't happened again yet, and it may not have been related to 10.5.7.

Cheers.

On thinking about it, it must have been around then that I installed the desktop clock app that I mentioned elsewhere in here... I'll try taking it off.

I hate intermittent faults, you can never be 100% sure that you've cured them

Single...

Thanks... I think

Something else got broke in the update too- I couldn't send from my @thinkbroadband.com email address. Bit of a snag for a moderator

Seems mail.app got updated to 3.6, and it wouldn't accept the SSL certificate. I had to set it to "Always Trust"

That sounds more like a problem at thinkbroadband than an Apple issue!

Apparently there is an oddity of some sort with the certificate, but it worked with Mail 3.5 and it still works with Vista and Windows Mail...

No problems on a variety of macs old and new.

OK, so I uninstalled the desktop clock I referred to earlier, and after a while it crashed again.

I'm also running a third-party screensaver, so I changed that to one of the built-in ones. Within minutes it locked up again, but this time I'd got some timings so went hunting in the system log. Found this:

May 21 12:45:10 bill-fords-imac kernel[0]: NVChannel(OpenGL): Graphics channel timeout!
May 21 12:45:15 bill-fords-imac kernel[0]: NVDA(OpenGL): Channel exception!  status = 0xffff info32 = 0x6 = Fifo: Parse Error
May 21 12:45:15 bill-fords-imac kernel[0]: 0000000c
May 21 12:45:15 bill-fords-imac kernel[0]: 00100000 00000039 00000000 00000800
May 21 12:45:15 bill-fords-imac kernel[0]: 00028212 00000328 00000000 00000002
May 21 12:45:15 bill-fords-imac kernel[0]: 00000000 beef3901 0000040d
May 21 12:45:15 bill-fords-imac kernel[0]: 0000000b
May 21 12:45:15: --- last message repeated 14 times ---
May 21 12:45:15 bill-fords-imac kernel[0]: NVDA(OpenGL): Channel exception!  status = 0xffff info32 = 0x6 = Fifo: Parse Error
May 21 12:45:15 bill-fords-imac kernel[0]: 0000000b
May 21 12:45:15: --- last message repeated 6 times ---
May 21 12:45:15 bill-fords-imac kernel[0]: NVDA(OpenGL): Channel exception!  status = 0xffff info32 = 0x3 = Fifo: Unknown Method Error
May 21 12:45:15 bill-fords-imac kernel[0]: 0000000b
May 21 12:45:15 bill-fords-imac kernel[0]: NVDA(OpenGL): Channel exception!  status = 0xffff info32 = 0x3 = Fifo: Unknown Method Error

with the last few lines seemingly repeating ad infinitum until I forced a restart.

The only thing (I think) that I haven't tried is to revert to a single monitor, because that would be a PITA. At the moment I'm running with the screensaver timing set to "Never", and keeping my fingers crossed

Anyone got any idea what the error messages in the log mean?

The nVidia graphics driver crashed, so either there's a problem with the driver, or with the graphics card. What card do you have?

In reply to a post by AlanH:

The nVidia graphics driver crashed, so either there's a problem with the driver, or with the graphics card. What card do you have?

From System Profiler:

NVIDIA GeForce 7300 GT:

  Chipset Model:	NVIDIA GeForce 7300 GT
  Type:	Display
  Bus:	PCIe
  PCIe Lane Width:	x16
  VRAM (Total):	128 MB
  Vendor:	NVIDIA (0x10de)
  Device ID:	0x0395
  Revision ID:	0x00a1
  ROM Revision:	3021
  Displays:
iMac:
  Resolution:	1920 x 1200
  Depth:	32-Bit Color
  Core Image:	Hardware Accelerated
  Main Display:	Yes
  Mirror:	Off
  Online:	Yes
  Quartz Extreme:	Supported
  Built-In:	Yes
L1917S:
  Resolution:	1280 x 1024 @ 75 Hz
  Depth:	32-Bit Color
  Core Image:	Hardware Accelerated
  Mirror:	Off
  Online:	Yes
  Quartz Extreme:	Supported
  Rotation:	Supported

It hasn't (yet) given any trouble unless a "full screen" process is running... not sure if that's any help in deciding between a software or hardware problem?