[LAU] Endlessly-stuttttttttttttttttering ALSA audio

Over the summer, I set up a Linux server running Airtime for a small micropower radio station in a remote area. All went well, except now I'm getting reports that the audio is stuttering endlessly on one 40ms frame of audio, like a CD skipping. The only way to get it to stop is to restart the liquidsoap playout engine (or to power-cycle the server, which is what they are doing now whenever it chokes). This seems totally wrong to me, but that's how it is. I've heard audio stutter briefly on machines, usually under heavy CPU load, but what could be causing it to stutter endlessly (until the application quits), on one frame with low/no load? What could be done to stop it from doing that? For reference, this is a 3Ghz P4, running airtime 2.1.2 which uses liquidsoap 1.0.0-svn, with Ubuntu 10.04 and kernel 2.6.32-38-generic-pae, hyperthreading on, 2GB RAM, 1.0.22.1+dfsg-0ubuntu3, and the liquidsoap instance runs typically 3-10% of CPU. I've looked in the logs at the time the error occurs, and.... nothing. Nothing at all out of the ordinary in the (noisy) airtime logs or the system logs. Because it's a remote server and I'm not on-site, I'm not interested in superstition: "try this, maybe it'll help, try upgrading to the latest version of x, y, z, try random-endless-variations". That-- and shrugs-- is all I've gotten from Airtime and Liquidsoap. I'd like to know exactly HOW this problem is occurring and what can be done to fix it permanently. I figured if anyone might have some clues where I could look to find this out, and what mechanism could possibly cause a single frame of audio to stutter endlessy, I might find some here. Thanks. -ken