It's definitely worth mentioning that you should not run over treasure jars to break them on levels with the motorcycle. It can glitch the treasure partially into the level geometry, making it impossible to collect. I assume reloading your last save will fix this, but if you hadn't realized what you'd done and intended to come back later to grab it, you will have to start a new game to reset all the jars.
I only encountered this once (Treasure 12 in Southern Mexico, according to this guide), so it may be only that treasure you need to be careful with, but I'd err on the side of caution.
Last edited by ZOMGie; 11-25-2008 at 09:28 PM.