Uncommanded Restarts

Can you check the system log in Console.app and see why you've been restarting?  This is the first I've heard of restarts; one of the things I've always liked about SAV for Mac is the lack of restarts, even when installing/uninstalling.

I think this is happening to me too.

8-core Mac Pro (2008 model) OS X 10.6.8. I was able to reliably reproduce the restarts when I was trying to run an Office 2011 updater at the same time that Sophos was running its daily auto-update. As soon as I waited until Sophos had finished updating then I could update Office without the computer doing an unplanned restart. But the computer restarted itself yesterday too when I was not doing anything at all and I believe it happened during the Sophos autoupdate. Prior to this, I was getting lots of unplanned restarts, similar to PC it was happening about 2 or 3 times a day. Replaced a hard drive and the problems went away for a few weeks until yesterday. No warnings - the screen just suddenly goes black and then the machine starts up again.

I can not say for certain if yesterday's restart had anything to do with Sophos but I will be uninstalling Sophos and seeing if the restarts happen again.

I can verify your most recent restart experience, as I've experienced it myself.  I thought it was associated with Lion, but a sighting on SL means it's not a Lion issue.  I hadn't associated it with SAV myself, but I'll keep an eye out for it in relation to AutoUpdate.

Further to my previous post I might be on the way to a fix for these uncommanded restarts. There is quite a long thread  about unplanned restarts at the Apple forums and it was kind of interesting to see quite a few 2008 Power Macs showing up in there.

My computer has not done an unplanned restart since I did these three steps:

1 - reset the system management controller (involves turning off the Mac and pulling the power cable out from the back of the Mac for at least 15 seconds)

2 - zap the PRAM

3 - go to the Energy Saver tab in System Prefs and click on the Restore Defaults button. You can then adjust the sliders back to how you want.

This suggestion was one of a bunch of suggestions in the thread. I don't understand the connection between my restarts and the Sophos auto-updates which I was experiencing but it is possible that the whole Mac had somehow become unstable as a result of something that was not related to Sophos. Anyway, it's been almost three weeks now without an uplanned restart so I'm hoping it's okay.

I'm having a similar problem on older Mac Mini.  

Really strange.  Sophos was installed.  All files scanned.  No suspected files.  

Sophos running in background causing computer to run very slow.

Turned Sophos off.

All seems fine.

Went to bed, got up computer is shut down

Toggled start button.

Kernel Panic!

Wrote down some of the data displayed on black screen and noted that it said:

"BSD process name corresponding to current thread:  Sophos AntiVirus"

It said a lot of other things but I thought this one was most relevant.

In all my years with Mac's this is first time I ever saw such a shutdown.

Held power button down until it went out.

Waited about 30 seconds.

Started machine with Pram Start

I forwarded the report to Apple.

I could not print out the report....any suggestions?

Turned on Sophos and now running a full scan, 

for life of me, can't understand how this could have happened.

This all on wife's Mac.

Any comments would be appreciated.