for those of you with experience with macbooks.

would using pc4200 work in them? or is it absolutely required to use the pc5300 they officially state?

instinct tells me, yes, like with any type of PC memory, as long as the memory is the correct type, you can downgrade speed.

This post confirms it

http://forums.macnn.com/66/ibook-and-macbo...ces-going-down/

I've no experience with Macbooks but hopefully this answers your question

thanks, it actually worked and so far seems stable.