VB6: Heavy form's controls load slowly and chaoticly

My problem ocurrs both in Windows XP and Seven, both throught VB6 and compiled, both in slow and fast computers.

In my software, when it has "heavy" forms (with much much controls), they are loaded or shown very unelegantly.

For example: In a form I have several Frames, each one contains many controls. When I hide one frame and show another, their content are drawn slowly. I mean, some textboxes borders are drawn first, then some other control's borders. What I want is that the change of frame is instantaneous, so if I record the screen, in one movie-frame, first frame is fully shown and next movie-frame, the second frame is fully shown, no intermediate states. (I'm not going to record the screen, i'm just stating very clearly what I want).

I reduced the unwanted effect by refreshing the form in some points, but it still does it, and some clients complained...

Thanks in advance, and excuse my bad english, which is foraign language for me.