I think my pedals are the Shimanos M959... I could be wrong about the exact number.
Anyway, are you twisting your heel out to get unclipped? For me it doesn't matter which direction I twist in - in or out - but it did take some practice to have the right strength/feel for it.

To get clipped, I push in to position the cleat and then I add a slight twist (I kick my heel out and then twist it in) while pushing down.