Tracey, we had some problems with credit about five years ago and worked furiously to get our ratings improved. Our concern was that blemishes hang on for seven years, even if your payment record is impeccable, so that was a concern for us, too.
I'm happy to say that our financing went without a hiccup. I toyed with the idea of getting "preapproved", just by asking for a copy of the credit application. I ended up sending in the deposit of $500 they always request, and received the rest of the paperwork. The ap is pretty standard stuff. I voluntarily paid 25% down, and got back our approval in about a week, and closed in three. Easiest thing ever.
I know there have been folks who have had some significant credit issues and Disney bends over backwards to work with them. If you're stable and not swimming in debt now, go for it! Nothing ventured, nothing gained, right?
I agree with the other posts ... I've never heard of anyone being turned down flat.