But that's the deal if you have unpaid moderators. They can't always be active on the forums. I'd guess if it's only you, or mostly you, who's doing the posting, that they got bored. Either that or they felt unappreciated and decided they'd had enough.
might want to look at Pms i had a mod that sent a pm to all my members about his forum, and they all moved
OK being a bit thick here and still learning the whole Admin thing as my first forum, but how do I check the PM's??
You could offer them revenue sharing too. Otherwise, maybe they're just losing interest in general. If so, offer your more active, mature members the opportunity to be a mod.