Pretty Sure.
I mean it's pushed in as far as I think it will go.
How do you exactly define properly seated?
Thanks for everyones help by the way, I really appreciate the quick responses.
Did you follow Apple's guide for RAM installation, I can't see how you could break the machine installing RAM, though if the computer can't detect it it can't start up...
Thank you for all your help.
Good end to the story.
All the RAM is now recognised and the MacBook is working fine.
But crikey, you really have to push them in firmly.