OK. I just took the old session and manually removed *all* inserts from the .ardour file. If I do that I can open, run, save, exit, reopen with no problems at all. Now I'll try a simple plugin. Cross your fingers ;-) Jan On Tue, 2004-05-11 at 11:09, Paul Davis wrote: > jan - don't run JACK in RT mode, you'll probably avoid lockups