I used to have jack working fine on my system, but lately strange things have been happening. Right now when I try: jackd -v -d alsa I get, too many servers already active I've also tried different variations on this (-R, etc), and using qjackctl. I can't find any other jack processes ("ps aux | grep jack" shows nothing). I get the same thing right after rebooting. Alsa seems to be working (aplay, etc). Can anyone give some advice? thanks.