text-shadow (and other css3) causes scroll lag

I've noticed that the more I use certain CSS3 elements (namely box-shadow and text-shadow) the more scroll lag exists on a page. I notice the problem on both FF4 and Chrome 10. Is there any good way to measure this or reduce it? I want good performance, but I also want to be able to use the shadows to create dimensionality between the various elements.

Thanks!