Audi S2 RPM turning at 6100

[th.b.w.]

Hy, i am Thomas from Germany and i have a problem.

Running VEMS 1.1.64 since January 2010 on an Audi S2, 3b engine with single coils LS2, hallsensor in the distributer, Siemens deka630, Gt3071, etc...

Now my problem is, that it take sometimes misfire in the range of 6100 RPM.
The logfile shows a wave at 6100 going from 5900 to 6300, sometimes it shows an trigger error.

What can it be, it is only in the range of 6100, sensors are new, spacer is drilled and set closer to the TDC pin, ign. wires changed, coils new, sparkplugs changed....

Thanks Thomas