I don’t think I ever noticed this before. But recently I noticed when I mark a seam and then try to select linked it only selects up to the seam as if the verts are not welded. It is a handy feature when you are unwrapping. It was happening and then driving me nuts trying to remove doubles until I realized why it was there. Anyone else notice this? It does not do this in 2.49. Or is it just a freakish bug?
EDIT: A little update, it only does this in Face select mode. And I am an idiot. It does the same thing in 2.49. lol! And so it is just a cool feature I never noticed. Ha!