Ok, so I think I killed my mythtv box.

I had a working install of R5A30 with a PVR350 configured for recording and TV out.

I tried to add a PVR500. I installed the HW, added the capture cards in myth setup, added the video sources, and restarted myth. Which all seemed to work, untill the forst scheduled recording started and the machine hung hard. Couldn't SSH in, and the keyboard was not responsive. Eventually I had to hard boot the machine. Now it will not boot properly. The Linux boot messages all look ok, (on the monitor), the TV flashes green for a second (as is normal when X is starting) then the machine freezes up.

SInce then I have discovered that R5A30 may not have the correct ivtv driver version for my PVR500, but not sure if this is waht caused the crash.

I was able to get into the machine using a shell boot from the LILO menu and found this as the last line in /var/log/messages

ivtv0 warning: Starting VBI after starting an encoding, seems not to work.

I fount this in the last line of /var/log/mythtv/mythbackend.log

Can't enable VBI recording
vbi: Invalid argument

These all seem to be related to the ivtv drivers and mythbackend. So why won't X start?

The XFree86.0.log file has the following warnings

Warning: font renderer for ".pcf" already registered at priority 0
Warning: font renderer for ".pcf.Z" already registered at priority 0
Warning: font renderer for ".pcf.gz" already registered at priority 0
Warning: font renderer for ".snf" already registered at priority 0
Warning: font renderer for ".snf.Z" already registered at priority 0
Warning: font renderer for ".snf.gz" already registered at priority 0
Warning: font renderer for ".bdf" already registered at priority 0
Warning: font renderer for ".bdf.Z" already registered at priority 0
Warning: font renderer for ".bdf.gz" already registered at priority 0
Warning: font renderer for ".pmf" already registered at priority 0

So what do I do next? Can I fix it without re-installing Knoppmyth? I am not a Linux pro, and feel over my head already, so spoon-feed please.

Easist thing to do would be to remove the pvr500 upgrade the ivtv drivers and try
putting the card back in.

I did remove the PVR500 but that did not allow the machine to get any further in the boot process. I am not sure how to go about upgrading ivtv in this state, since all I have is a very basic shell. I don't have access to the partition where myth lives, and gcc doesn't seem to work. Any Idea how I can get the machine to a more functional state? Would it be easier to boot from the knoppmyth install CD and then exit out to a shell?

I am going to be on the beach for about week so maybe someone else can give you
the details.
First those font errors are nothing to worry about.
second I think that it adding the second card to mythtv-setup that is now
causing your problem. The setting is stored in your mysql database.

reboot to single user
remount read/write
take the backend out of init.d so does not start
reboot
apt-get update
apt-get install phpmyadmin
from another machine login phpmyadmin
remove the pvr500 from the setting table.
add the backend back into init.d so that it starts at next boot
reboot

Thanks for the help, but it is all bad now. The machine went down hard when I tried to do this and the file system is hosed. Eight hours of effort later has yeilded no recovery. I give up and am re-installing.