Initialize listview item size.

[Duane Clark]

Duane Clark wrote:
> 
> It paints the headers. And the problem comes about because in 
> LISTVIEW_Paint, a test is made for the first paint, and if it is the 
> first paint, the item size is updated.
> 

I guess I should have said something like "...and only if it is the 
first paint...". Hopefully that was reasonably obvious anyway.