Georg,
XXHighend should be able to add a configurable synchronizing sequence added in front of the track.
By itself this is true, but the problem will be somewhere else. No clue where or what though ...
I think we talked this through before, there are (or were) many users using a Juli@ (former NOS1 version), and no such thing existed.
Try moving it to another slot, or think in the direction of PCI otherwise ...
Also, you could try to determine whether there is a difference regarding this issue between KS Special Mode and Adaptive Mode. I can expect something like this happening with Special Mode, but then you should try another driver (again).
Peter