According to BestBuy.com it is DDR2. Not saying you're wrong (I have no clue) but this is the ad online:
QUOTE
Gateway Notebook with Intel® Celeron® M Processor 360
Model: MX3215
With this lightweight notebook, you can surf the Web, check your e-mail and instant message your friends on the go, thanks to the built-in wireless technology. Transfer digital pictures easily using the 4-in-1 digital media manager.
Intel® Celeron® M processor 360 with 400MHz frontside bus, 1MB L2 cache and 1.4GHz processor speed
256MB DDR2 memory for multitasking power, expandable to 1GB