Hat geantwortet auf: Problems after upgrading ram from 2gb to 4gbThere are easily 10 different threads I've found reporting this very issue over the last couple of years with earlier model Intel MacBooks not recognizing new RAM unless one of the original RAM is in one of the slots. The advice is always the same: Bad RAM, wrong RAM, installed incorrectly, you're doing it wrong, etc. In no instance has anybody reported a working solution. If anybody out there has a suggestion for addressing this weirdness, I'd be grateful for the help. Thanks.