Reported in forum post http://css3pie.com/forum/posting.php?mode=reply&f=3&t=110
Linear gradients which are specified as vertical or horizontal end up at a very slight angle. This is probably due to the conversion of angle values from normal CSS3 angles to the weird VML-land angles. We should add special-case code to handle vertical and horizontal angles to avoid the conversion since it's not needed.
Fix for issue #64: Prevent rounding in BgPosition calculation and add…
… special-case logic for perfectly horizontal/vertical angles to prevent them from getting slightly off.