Most embarassing interview moments and maybe a few interview tips as well

I've got a question:
Usually you get interviewed for a specific position, right? Well, for my first and only interview job (Wal-Mart) I was being hired as a cart-pusher. During the interview I asked how quickly the "associates" are able to transfer between positions. Apparantely they thought that was presumptious, because they were like "well, we really need a cart-pusher...". I realize Wal-Mart's a bad example, but I always thought asking about internal mobility was a good expression of interest in working for the company. I need to look for a summer job soon, so was this a bad question to ask?

Jam it back in, in the dark.