laptop in question is a Toshiba Satelite L640D. OS is ubuntu 13.04. Sometimes when I let it lock its screen (screensaver set to 3 minutes with password protection), when it comes back it will freeze on me with the
message on the screen. Only way to get it working is rebooting (pressing and holding power buttom will do, which would make me think some stuff is working). Once I reboot I find nothing (or I am looking at the wrong stuff) in syslog or messages or dmesg or lastboot.
[ 6562.038340] (Firmware Bug): cpu1: try to use APIC500 (LVT offset 0) for vector 0x400, but the register is already in use for vector 0xf9 on another cpu
I have not been able to isolate what causes that to happen: I might have no application running or ton of them. Or be connected to a charger or running out of battery. Or laptop might have been sitting on my desk while I go get a drink of sleeping in my bag for a day.