Any fellow iStockers will know that they refuse to accept any open paths in their illustrations and it can be quite a chore to go around your illustration manually closing them all up again. However after a little Googling I came across a wonderful plug-in filter that closes them all up instantly for you. And it does a host of other cool functions too. Check out Point Control for yourselves. It works with CS3, CS4, and CS5 versions and the site has several other pretty darn useful plug-ins to tinker with as well.