Hi, Lutz

You are right. I found un-killed DE via 'SUSPEND' and 'SET VIEW ON' after
calling form was re-activated, and which was prior form's DE.
I looked up my code 3 times whether there would be variables not dimensioned
locally or properties not yet set to .null. on destroy, but i failed ,
totally exhausted and near to eat my P.C...^^;;
4 forms were subclassed from same parent class and others killed without
problem except this one, in which has only just a few of his own method.
I have to check one more time from the form itself along class tree, top
class is _ffc\_form class and all my forms uses his release method.
Thank you for kind help again and have a nice week end.

RGDS
HK.Lee