Basically with this bug, when you have dynamite out and you have molotovs set as your last used weapon, if you hit the button to light the molotov before the weapon switching animation finishes playing, it has to stop and do the dynamite-lighting animation, and THEN it switches to the molotov. Very annoying thing. That good second or so delay has gotten me killed more times than I care to admit.

But seriously. Fix it.
If you care to see an in-game demo of it, I put it here...
http://www.megaupload.com/?d=3GEAV26G
Sorry that I don't have fraps or anything like that, but hopefully that'll give you a general idea of what it looks like, and how annoying it is.