[LAU] Random RT performance after reboot

Hello, Okay, I'm giving up on trying to explain this by myself and am seeking educated guesses from this list... Sometimes, after a reboot, my system's RT reliability seems glitchy and jackd gets killed by its watchdog, usually after running a few hours. At other times, jackd will remain rock-solid, literally for weeks, until I shut down my system. It's usually a matter of rebooting until the problem disapears. Setup: - Debian Testing AMD64 - USB soundcard (UA25EX) - jackd version 0.120.2 - jackd options: "-R -P55 -t1000 -dalsa -d hw:1,0 -r44100 -p64 -n3 -S" - rtirq set to give highest priority to USB irqs So far I have: - Tried to change which port various USB devices use, thinking some conflict might be causing this, without any result. - Until recently, I thought that booting the system with the soundcard plugged in solved the problem, but proved wrong. Any ideas? Cheers, S.M. --