[linux-audio-user] problem: jackd, real-time, permissions, RLIMITS

I've been working on this problem now for days, and I can't see where my mistake is (if I have made one). I have two identical computers running Gentoo with the proaudio overlay. I have 2.6.16-rt29 working on one computer, using RLIMITS. I can start jackd through qjackctl with the realtime option, 64 frames/period, 2 periods/buffer. I get no error messages and only get an occasional xrun when starting new applications. I have tried to duplicate that setup on another computer; however, I always get these errors, which don't occur on the properly-functioning computer: cannot lock down memory for jackd (Cannot allocate memory) cannot use real-time scheduling (FIFO at priority 20) [for thread 49156, from thread 49156] (1: Operation not permitted) cannot use real-time scheduling (FIFO at priority 10) [for thread 65541, from thread 65541] (1: Operation not permitted) This is followed by tons of xruns. Here is more relevant information on my configuration (identical on both computers): renick@localhost ~ $ uname -a Linux localhost 2.6.16-rt29 #1 PREEMPT Sat Jul 22 21:16:25 JST 2006 i686 Intel(R) Pentium(R) M processor 1.70GHz GenuineIntel GNU/Linux renick@localhost ~ $ groups wheel floppy audio cdrom video usb users # /etc/security/limits.conf # REALTIME support for audio group users @audio - rtprio 90 @audio - nice -5 @audio - memlock 512000 localhost renick # equery which pam /usr/portage/local/layman/pro-audio/sys-libs/pam/pam-0.78-r6.ebuild localhost renick # emerge -s pam * sys-libs/pam Latest version available: 0.78-r6 Latest version installed: 0.78-r6 localhost renick # equery which jack-audio-connection-kit /usr/portage/local/layman/pro-audio/media-sound/jack-audio-connection-kit/jack-audio-connection-kit-0.9999.ebuild localhost renick # emerge -s jack-audio * media-sound/jack-audio-connection-kit Latest version available: 0.9999 Latest version installed: 0.100.7-r3 This version, 0.100.7-r3, is the same version that is working on my other computer. I've asked on the proaudio list about this problem, but I haven't received an answer so I am asking here (is a four-day lag cross-posting? if so, sorry...). What could be causing the jack errors? Are there any other places besides /etc/security/limits.conf that I should be checking for correct configuration? Advice? Thanks! Renick