Hi Jörg!

I know nothing about your problem, but since no-one else seem to answer...

>Is it only me, who gets this behavior?

Probably, since no-one responds.

>Where should I look for finding the error?

A wild guess would be to try moving your code to BeforePost rather than
AfterPost (assuming qryAufwand is your "detailset"). It shouldn't matter
since you only change DefaultValues, but AfterPost is for changing other
datasets, not the dataset itself.

HTH or that someone else comes up with a better idea,
Set