I was going to post about this myself, it's very odd. I wonder if they've had a cull of old ads, or introduced stricter requirements for posting or something?
But I'm just speculating, I've no idea what the cause is, and I'd love to know too. It's not the greatest place for finding SPs, but it's nice that there's at least some alternative to AW out there, so I'd hate to think it was about to become less useful.