Thank you everybody for your posts. I have a few questions to maybe make things more clear!

Do the shavette and the straight razor have the same way of using (or almost?) Because with the shavette its no problem at all to have a good clean shave. And if i use the straight razor it feels like its "skipping".

I then assume that it's all about the sharpness of my blade. I didn't hone it, just took it a few times over the leather belt. I don't have any honing experience and here in Holland i don't know any "honing masters".

If using the shavette is verry different than using a straight razor the problem might be the shaving technique.

Any more toughts? Thanks!