Audio clips stop playing, one day after reboot
I've only been running Linux for a year. Running Debian Squeeze, AMD64. I watch/listen to video clips, mostly on political blogs. IceWeasel is the browser. Adobe Flash Player non-free plug-in is installed. About three weeks ago, the audio became garbled, with unintelligible noise that goes from high to low volume at about 2 Hz. A reboot fixes it. 18 hours later it still works. By about 24 hours post-boot, the problem recurs. The system plays CDs well even when the audio clips won't play. Audio-only clips have the problem.
I'm also trying to figure out a problem with "Volume /tmp only has ??? Mb free".
I am at a loss for ways to begin to trouble shoot this problem, or even to be able to succinctly describe it for a fruitful search.