OK, i hacked it..
copied MODULE set_update_flag. wrapped it all into an IF key IS NOT INITIAL - ENDIF.
Now it works, until someone wants to Regenerate the whole dialogue.
Imho it is only a Workaround, but i guess to have live with that...
Thank you Steve, i tried to avoid hacking my dynpro, but i guess this time it is a feature and not a bug...
regards
Jan Martin