HTML window width--always just too small!

[Peter Bloomfield <PeterBloomfield MindSpring com>]

Every time an HTML part is displayed in my setup, it's always rendered 
for a window that's a fraction wider than the one it appears in, so it 
has a horizontal scroll bar at the bottom. If I resize the window and 
rerender, it adjusts to the new size, but still seems to overestimate 
the window width.  Does anyone else see this, and can anyone help me 
fix my setup to avoid it?

Thanks for any help!

Peter