Jack rt problems in hardy

[rob free]

Hi everyone,
I'm having lots of trouble running jack (from jackQtl) in ubuntu studio
8.04 . I am using a USB sound card : Alesis io2 and Jack Xruns like
crazy on all settings! I get some error messages at start up :



11:01:39.739 Startup script terminated with exit status=256.

11:01:39.740 JACK is starting...

11:01:39.740 /usr/bin/jackd -R -P70 -dalsa -dhw:1 -r48000 -p128 -n3 -D
-Chw:1 -i2 -o2

11:01:39.744 JACK was started with PID=7429.

jackd 0.109.2

Copyright 2001-2005 Paul Davis and others.

jackd comes with ABSOLUTELY NO WARRANTY

This is free software, and you are welcome to redistribute it

under certain conditions; see the file COPYING for details

JACK compiled with System V SHM support.

cannot lock down memory for jackd (Cannot allocate memory)

loading driver ..

apparent rate = 48000

creating alsa driver ... hw:1|hw:1|128|3|48000|2|2|nomon|swmeter|-|32bit

control device hw:1

configuring for 48000Hz, period = 128 frames (2.7 ms), buffer = 3
periods

ALSA: final selected sample format for capture: 24bit little-endian

ALSA: use 3 periods for capture

ALSA: final selected sample format for playback: 24bit little-endian

ALSA: use 3 periods for playback

JACK: unable to mlock() port buffers: Cannot allocate memory

JACK: unable to mlock() port buffers: Cannot allocate memory

11:01:41.796 Server configuration saved to "/home/rob/.jackdrc".

11:01:41.797 Statistics reset.

11:01:41.799 Client activated.

11:01:41.800 JACK connection change.

11:01:41.804 JACK connection graph change.

cannot lock down memory for RT thread (Cannot allocate memory)

11:01:56.259 XRUN callback (1).



Does anyone know why jack cannot allocate memory? Any suggestions?
Thanks for your time!
Robin