PowerMac G5 Ram Upgrade?

So, I have a dual 2.3 processor G5 tower with 1gb of ram, split between two 512mb sticks. I decided I wanted to upgrade, so I ventured to my local Circuit City and picked up a 1gb stick of Kingston PC3200 ValueRam (I know, not the best ram, but it was cheap and I'm poor).

I installed the ram into the computer, all fine and dandy, but now when I boot and check System Profiler, it's only recognizing the two 512 sticks that were already there. My question/s are

1. Why is it not recognizing that ram? Do I need to configure something on the computer

2. If the ram isn't showing up is system profiler, is it possible that it's using it but not showing?

3. What would be the best configuration for the three sticks? I assume that the 1bg should go on one riser with the 2 512's with the other, but will it make a difference which goes where?

Thanks in advance;D

I think you have to install the RAM in pairs so you would need to install 2- 1GB modules.
Bryan

As was stated by bryphotoguy, you will need to buy two 512 for 1GB or get two 1 GB for 2GB of memory.