I have been having my MacBook running Elementary os freeze up I have tried other Debian and ubuntu os's It freezes up during downloads and background changes. I have upgraded the ram to 8GB and am wondering if that would make it unstable?
if its a 2009 chances are its an intel core 2 duo [64 bit processor] teamed with a mac 32 bit motherboard.. if its a very late 2009 it may have an intel I series processor [again 64 bit] but with a 64 bit motherboard.. macs of that age do not normaly support more than 4gb ram.
which version of elementry were you running?