[AccessD] BIT OT: Any VB Gurus out there?

Hi Team
Working on VB code.
Code works fine in 98/ME (Shudder) but there are visual issues and
errors in 2000 or XP

The code 'draws' lines/coordinates into a Picture Box 
We have managed to get the code to kinda work in XP by changing A few
integers to longs.
Names are -
"frm_Control" for the VB Form
"ssTab" for the Tab Control
"Picture1" for the picture Box

But here's the thing

In 98/ME the drawing is done and you see the lines after clicking a
button. Lovely.
With the modified code in XP the code draws the lines but you don't see
'em.
But if you click on a Tab then come back to the PictureBox in question
then you see the lines.

So how do I refresh the contents of a picture box in VB?

Frm_Control.Picture1.Requery Doesn't work  - I get
Compile Error 
Method or Data member not found

So...any suggestions on how to 'redraw' or 'refresh' or 'requery' this
thing with out changing tabs.
BTW - There is very little code in the TabChange code. It has nothing to
do with repainting etc.

Many thanks

Darren