Yep, I agree with Mike's suggestion. You should only use Crucial RAM when it comes to Macs. The RAM that Apple uses to build their Macs uses chips manufactured by Micron, and Crucial is the sales department of Micron.
Even in a PC, I've never had any problems with Crucial. I've used various different sticks, with varying capacity and varying speeds over the past few years, and have not encountered a single RAM-related problem. Go Crucial, you won't regret it.
AMD Sempron 2600+ (Socket 754; 1.6GHz)
768MB Crucial PC2100 (I know, I really need PC3200 :()
ATI Radeon 9200