[linux-audio-user] multiple simultaneous instances of xmms (or other graphical app) w/JACK?

Hi all, I would like to simultaneously play 2 audio files and mix their output via JACK. I want a JACK solution because I also have BruteFIR in the workflow. I can play a single instance of xmms through JACK without problem and I can open multiple instances of xmms without problem - once enabling that option. Here's the hitch: when I try to play audio files with the two xmms instances, the first works fine, but the second gives an error complaining that it can't open the output device and to check that another program isn't blocking it. I'm using xmms-jack-0.14 as the output from xmms into JACK, but it doesn't seem to handle multiple instances. Am I correct and is there a workaround? Is there another/better (lightweight w/GUI) jack-aware audio player that I could use instead of/in addition to xmms? I'm primarily playing .mp3 & .wav audio files. Distro is a fairly stock FC4 (with FC4 kernel slightly massaged & rebuilt to use realtime-lsm module) JACK 0.100.6 QJackCtl 0.2.18 Thanks in advance, Rick