Hi bbudd,
I have no caper seeds but I have experience in germinating the seeds.
Caper seeds, once dry, become dormant and can therefore germinate erratically - they can be up in 3 weeks, or may take 3 months!!
Soak your seed in hot water (about 40 ºC ) for a day. Stratify your seeds by placing them in a Deno-bag in the fridge for at least 2-3 weeks - or longer if the other people that you share the fridge with don't mind. :-)
good luck.
Andy