Performance in Ubuntu Studio 12.04

Hi
Not sure if this the right forum, but I just installed Ubuntu Studio 12.04 and I have som delay in the QSynth parts running Qtractor. I have the same settings as i have in Ubuntu Studio 11.10.
Any ideas where to look, tweak or something I missed?
I use JackCtl, QSynth and QTractor as is from 12.04. I built the QTractor in 11.10.
BR
Mikael