IceLeopard

I was seeing that too, and it wasn't with either the digest or the "what's new" function. I was doing an advanced search for washing "cotton batting." About half the threads that showed up in the results gave me "invalid thread" when I clicked on them.

Most of them were older threads, so it was highly unlikely that they had all been moved in the few minutes between my initial search and when I clicked on them. If they had been deleted or moved to a "moderators only" part of the forum, they wouldn't have shown up at all. Date did not seem to matter. Some older threads gave me errors, but others even older came up just fine.