[Edit] I found the bug report for this one; there doesn't appear to be a solution. It's bug #54621: "Hardy final 8.04 generic works fine. -rt version panics." was the last relevant comment. The realtime kernel is essential for the work I want to do, so I guess I have to wait until it's fixed and reinstall. My original post follows.
I installed Ubuntu Studio in a CD MacBook. The install seemed to go well, but booting is hit or miss. Sometimes I can boot in recovery mode; sometimes not. A couple times I got a normal boot. Sometimes in recovery mode it just goes to a blank screen; other times I get a message like this:
"MP BIOS bug: 8254 timer not connected to IO-APIC.
Trying to set up timer (IRQ0)through the 8295A(something)...failed.
Trying to set up timer as Virtual Wire IRQ...failed.
Trying to set up timer as Ext-INT IRQ...failed.
Kernel panic - not syncing - IO-APIC doesn't work! Boot with APIC=debug and send a report. Then try booting with 'noapic' option."
Sometimes with a regular boot, I will see something about IO-APIC flash briefly on the screen, then it will either boot to the desktop, or I will see colored patterns as the screen flashes on and off before finally going blank.
I can't figure out how to access boot options like noapic. I can't even find a reference to "IO-APIC" on the forums. Does anybody know what this means, or what to do about it?