Wait, really? I'm a native Midwestern/Great Plains American English speaker (I remember reading the Harry Potter books as a kid and wondering why all the -er words were spelled wrong) and I say "PRY-mer." I have never heard anyone say "PRIM-mer" in my life.
I too have never once heard primmer. Not that all words follow the rules, but it doesn't make sense (vowel-consonant-vowel has long sounding vowel. That page also has the audio file links backwards (regular vs irregular). The file labeled irregular pronunciation sounds like primmer.
I am too. I've heard of the supposedly correct pronunciation, but I can't bring myself to use it. The "PRY-mer" pronunciation is more common in practice.
Am...am I being punk'd...?