[MT-AU Public] PPPOE and Fast Path

For those of you running Mikrotik as a PPPOE LNS what are you doing with Fast Track/Fast Path when you are using dynamic simple queues for users ? We seem to have hit and miss results with it, sometimes it works, sometimes it doesn't. If we have a simple queue not matching any upload traffic we have to disable fast path and it works again. Any thoughts or experiences in this area ? We even have some routers where some customer queues work ok and others don't match upload traffic with default settings for fast path. Strange... Regards Paul