This is a software problem which needs to be fixed. It would be worth playing with the oversampling shift and the reporting frequency. It also might be wise to look at the tslib dejitter plugin which is _supposed_ to cure that, but for some reason it doesn't.
It's on my todo list, but I wouldn't be sad if someone beats me to it ;) Regards, :M: -- Michael 'Mickey' Lauer | IT-Freelancer | http://www.vanille-media.de

