Who was your Vogele rep? Ours was Tom, he covers Eastern Canada. Our Vogele has a vibratory screed, no tamper bar on ours. Not maintianing a consitant head of material, will cause problems. Not paving at a consistant speed can also cause problems. Are your augers set at the proper hieght? They should be around an inch or so above the bottom of the screed. If you manually control the screed using the screws does it still wash board? What kind of material are you using? We use super pave here, it musy be laid thicker. I'm thinking min course thickness is 3X the average course agg.
Just some sugestions, Telescooper