Ok, Im new to Macs, so bare with me. I recently bought a Mac G5. It was sold to me as a 2.3 Dual Core, which should make it a late 2005, model # M9591LL/A. When I went to order more memory from Other World Computing, their site said if it was a dual core it would have a line under Hardware Overview which would say the # of cores. It doesnt. To further confuse me, when I look under Memory on the machine, I see that the two following types are installed: DDR2 SDRAM PC2 4200U-444, and DDR2 SDRAM PC2 3200U-288. That I dont understand. Or, is my machine a model # M9748LL/A ? Or am I reading the page at OWC incorrectly? Thanks in advance for your help!!