The Adobe Photoshop's Render Lighting Effects plug-in does not work in 64bit. It does however work in 32 bit. You will need to run Adobe Photoshop in 32 bit mode. To run Photoshop in 32bit you will need to have Rosetta installed on your machine. To find out how to install Rosetta go here: http://docs.info.apple.com/article.html?path=Mac/10.6/en/27987.html

Note: Unless you are working with massive files (2.5 to 3gig) the speed difference between 32bit and 64bit, is not noticeably significant. Where you will see the speed difference is if you use smart filters, specifically during opening and saving. How to negate this speed loss is discussed in the body of the book. I did not discover this issue until after the book went to press because some of the software that is given away for free was not upgraded to 64 bit until just after publication. Hopefully in a future update of CS5 this oversight will be addressed.