svg stroke rendering

Hi,
recently noticed that horizontal and vertical strokelines appear blurred
if the are placed at an integer pixel position and as expected only if 
on float pixel postions.
Does anybody know if there is a way to avoid this behavior - ( appears 
on opera too )
See my example at http://go2ghana.net/devel/svg/rectStroke.svg
Mousedown on the elements moves them by 0.5/0.5

Happy new Year,
Axel