Thanks for the tips. I called the Pgymy folks - they said while that its pretty uncommon, they have heard of the pinhole leaks developing, and have had it happen on a few of the boats they've built themselves. They also had no idea why it would happen.

They suggested using a syringe to squeeze/push unthickened epoxy into the holes. They said to use straight epoxy, rather than thickened, because you're trying to get the epoxy to saturate the hole (through capillary action).

I agree that simply rolling/painting another coat of epoxy over the hull won't work - I rolled two coats over the hull, and still had the pinholes.

I marked (31 on port side, 18 on starboard, all but 3 on the lower hull chines), sanded and epoxied the holes last night - I'll let you know how it turns out!

Thanks for the advice