Sand - 2:23 pm on Apr 20, 2012 (gmt 0)
Thanks, Andy. You're absolutely right -- it's just about impossible to diagnose these things when there aren't any glaring technical errors or anything of the like.
The influx of links could just be a coincidence, but I sure hope that's what is causing this sandbox-type effect. The content on the site is quality, and the all inbound links are quality editorial links except the ones I can't help (a couple hundred spamblogs trying to get trackbacks).
I'll run through the site and do some general cleanup type stuff, and hopefully things will come back to normal shortly.