Resizing controls manually

I have three WebListBoxes on my web page.
When the Resized event is fired I set the top left and height of each of the three WebListBoxes such that the three are the same size and occupy the page equally from top to bottom.

[code]dim y1 as integer = TopListBox.top
dim y2 as integer = self.height // The web page.

System.DebugLog("y1 = " + str(y1))
System.DebugLog("y2 = " + str(y2))[/code]

[quote]2013-07-09 10:25:31.371 AM My Application.debug[10405]: y1 = 232
2013-07-09 10:25:31.371 AM My Application.debug[10405]: y2 = 317[/quote]
For some reason height is only 317… which is not true.

If I use my mouse and just nudge the bottom of the web page to make it resize THEN it works perfectly.

[quote]2013-07-09 10:27:16.257 AM My Application.debug[10405]: y1 = 232
2013-07-09 10:27:16.257 AM My Application.debug[10405]: y2 = 1092[/quote]

Am I missing something in the order of which events are fired and am not drawing my interface in the right event?
Is this something to do with the min/max height?