You're posting from Linux I bet. Your last two links led back to the post. The Linux clipboard messes up on me sometimes too and I've never figured out why for sure. By "messes up" I mean that copying something, then pressing ctrl-p vs. using the middle mouse button can paste two different things. Different clipboards I guess.
DE

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic