MacFixIt reader --- reports that the Corsair Micro-manufactured RAM modules he bought at Fry's are too tall to properly fit into his Power Macintosh G5 Dual 2 GHz.
"I purchased the a 1 GB kit (two 512 MB Modules), PC3200 Pro speed. I love the flashing LEDs on the modules. The problem is that the modules are about 1/8" too high and therefore do not allow the PowerMac Fan Assembly to be pushed back into position. This creates a problems closing the door to the Power Mac. The sensor knows the door is not closed right, so the PowerMac is throttled down because of a problem with cooling."
"Fry's says this is an issue with Corsair, and Apple said that the G5 meets the electrical and physical specs for the PC3200 RAM module, therefore this is a Corsair problem."
As this report indicates, you should always check with the manufacturer of your PC3200 RAM module to make sure it is guaranteed to be G5 compatible.