[LAU] Jack conking out, How to debug?

Hello, all, So, thanks to the excellent advice received on this list, I recently purchased a Roland UA25EX and it works just great, and out of the box at that. Also thanks to this list, I now have my RT kernel sorted out, lean and mean as ever. All great! With my (crappy) internal sound interface, I used to be able to leave jack running for days at "-p128" without any problem, at least with my new kernel. With my new USB soundcard, however, jack works flawlessly for a few hours and then abruptly exits saying something to the effect that jack timed out and the watchdog is doing its painful duty. Here is my jack command-line: $ jackd -P61 -t100 -d alsa -d hw:2,0 -p128 -r 44100 I tried adding "-v" for good measure and redirecting to a file, here's what it looks like before the downfall: -Couple 100K of boredom- [...] load = 0.2478 max usecs: 4.000, spare = 1447.000 load = 0.2273 max usecs: 3.000, spare = 1448.000 load = 0.2859 max usecs: 5.000, spare = 1446.000 (and then tonnes of) **** alsa_pcm: xrun of at least 0.029 msecs **** alsa_pcm: xrun of at least 0.025 msecs **** alsa_pcm: xrun of at least 0.026 msecs **** alsa_pcm: xrun of at least 0.024 msecs ---and so forth until jackd gets killed. Does anyone know what the problem could be? Is something wrong with my jackd command-line? Is there anything further I can do to debug? Cheers, S.M. --