Sea & Sea recommends o-ring maintenance annually. I push it to every two years based on the conditions I normally dive in (no sand or gunk). Three years is pushing it. If I was in Florida I'd take my housing over to Reef Photo and ask them to go through it fo me. It's all the internal o-rings I'd be worried about. The first one to start to leak is usually the shutter release since it gets more rotational wear.
Thanks Steve! That's what I was thinking, next time I'll be down there for a shore dive, I'll take it to them. I completely forgot about the shutter, plus haven't used it in over a year.