I'm finding more and more modules where you can only use a single kit and not 2 kits.. due to the modules design..... due to the motherboards own design usually as well, where 2 modules will not fit side by side .... aka.. can't use 4 modules...
ram i'm speaking of course..
i'm currently considering getting 2 of these kits
OCZ Technology | Products | Memory | OCZ DDR2 PC2-8500 Reaper HPC 4GB Edition
as the other modules won't fit (even ocz see's the issue by placing a note on the website.. about it)