Form dispay not correct. How can I address for every theme?

I didn't quite know where would be appropriate to post this, but since it's
due to the drawing of forms I figured I would stick it here.  What I need to
know is what is up with designing an app under an XP bubble theme and then
it not displaying the forms correctly under the regular windows theme.  Or
vice versa.  I attempted to set heights with clientheight instead of height,
but that didn't help either.  Anyone know how I can resolve this?  Thanks.