Line command causing Screen Disruptions

I am using the line command to plot X and Y points in this manner:

If Z! < 0 then
frmMain.Picture1.Line -(X!, Y!)
Else
frmMain.CurrentX = X!
frmMain.CurrentY = Y!
End If

I added this code to my WORKING program. Now when I run the file that contains the X Y coordinates, the borders around my labels go from 3D to flat, none of the Command buttons works, and it does not change any of the icons that tell the user it is plotting points. But when the program finishes the XY plotting appears all at once, in the correct manner. When I comment out the above plotting code, the program changes icons correctly, the command buttons works, and the labels are not affected, but the XY plots are not drawn. Does anyone know what would cause such a problem??????????? The above code is contained in a FUNCTION in module1.bas. THANKS FOR ANY DIRECTIONS!!

Try placing a DoEvents wheverever you think the freezing is occuring. This could clear things up a bit.