- ya! Ya kno, it was too much stuff like this that always kiboshed my previous attempts to get a linux box up and running. This time I have two running distros, and this is more like fine-tuning - but almost "the straw on the camel's back" fine-tuning. Sheeesh.
Further update, and trail for those who will follow. KVM switches ain't dumb devices any more. Haven't been for some years, and most of you wouldn't want one if it was. That's because all "plug and play" relies on a "conversation" with the OS. Keyboard, mouse, monitor, other externals - they talk back.
Now, that said, this VL box has been running, using the KVM switch, all morning. I did make an edit to xorg.conf, but I'm not sure that is actually what made the difference. That's because I may have made an unintentional change this morning from when the machine bugged out on me last week - I booted the VL6 with the monitor up, and the KVM switch turned ONLY to the VL machine. Turns out this is at least one very important time when using a KVM switch. If the starting OS doesn't get feedback from the I/O devices, it does the best it can with default settings. Which may be pretty screwed for your real settings. I also used the nvidia setting gui to rewrite the xorg settings towards a more manual control of the refresh, as per the Wikipedia link (for VGA Connector) that I posted earlier in this thread. http://en.wikipedia.org/wiki/VGA_connector
AND, dummy me, I finally got out the KVM user's manual, and read that, too. Turns out there is a keyboard reset hot key combination. Might have helped last week, might. Maybe not, too, can't really tell at this point, without recreating the initial lockup, which I don't care to do, thank you very much.
So, what I've learned:
* If it's a critical application, there are expensive (+$150-$1,000) KVM switches that are designed to work cross-platform and with multiple hardware formats (eg PS/2, USB), maintaining dummy video signal etc.
* Normal (i.e. cheap - $20-60) KVM switches, that are ~ 4 yr old or less, will do the needed communication, but may have issues that need to be learned about to manage. This is not just a Linux thing - I've got a cheap PS/2 KVM from a good mfr, whose stuff I have had a lot of good experience with - and that KVM won't work with my Windows box.
* If there are issues, look to the startup. When attached through the KVM, startup the box with the monitor, keyboard, and mouse attached (KVM switch turned on to the starting machine).
* Do new hardware without the kvm. Get it running then, with the machine OFF, put the KVM back in the loop. The Wikipedia entry above tells you how to use Nvidia's gui settings to rewrite the xorg.conf to help prevent the startup issues. If you've got different hardware, at least you are looking in the right area for answers. Any one of 4 components could have caused my symptoms: the monitor, the vid card, the keyboard, and the mouse. That's right - the keyboard or the mouse could have also caused my issues. But if it's the keyboard or mouse, the KMV mfrs just recommend you try a different one.
* When all else fails, read the user's manual again.