Here is my code... works fine in either VFP7 or VFP6 on the forms RESIZE event. Note: Height is last. Try swapping the width with the height. You will notice that when you resize that the size of the pageframe is messed up.
P.S. I use ASSIGN and ACCESS with Lockscreen to automatically refresh the form once LockScreen is reset to False.
LOCAL llLockScreen
llLockScreen = THISFORM.LockScreen
DODEFAULT()
WITH THISFORM.pgfMain
.TabStretch = 0
.TOP = THISFORM.ctxtName.Top + THISFORM.ctxtName.Height + 5
.LEFT = 2
.WIDTH = THISFORM.WIDTH - (.LEFT * 2)
.HEIGHT = THISFORM.HEIGHT - .TOP - .LEFT
ENDWITH
THISFORM.LockScreen = llLockScreen