[linux-audio-user] Can't get rid of xruns

Hi, I'm trying to set up my Ubuntu Dapper system to work reliably with reasonably low latency, but I'm unable to really eliminate xruns. It works quite well most of the time, but sooner or later I'll inevitably get xruns, usually when starting/closing jack-apps, or sometimes when starting/stopping playback. My machine is an Athlon XP 3000+, with VIA chipset and 2 SATA disks. The sound card is an M-Audio Audiophile 2496, and my aim would be to run jack at 5.8ms latency (-r44100 -p128 -n2) or less. I already tried pretty much everything I could thinks of, that is: - Installed a realtime kernel (currently 2.6.16.1-rt11) - Used the nv display driver instead of nvidia - Switched PCI slots around so that the Audiophile doesn't share an IRQ with the graphics card (an IRQ solely for the Audiophile doesn't seem possible, it now shares an IRQ with a SBlive) - Changed filesystems from reiserfs to ext3 (/) and xfs (/home) I'm running jack at rtprio 70, and also set the sound card IRQ's priority to 99, but none of that seems to make a difference. I have latency tracing enabled, but I can't make head or tail of it, to me it looks like the xruns occur at random... Now I'm at a loss. What else can I do? Thanks, Dominic