I've heard Rush, Brian Sussman and pretty much everybody else do this sort of thing occasionally. Means nothing, but exposes the fear the left has for Sarah.
This is why I am a big fan of the marine “corpse man” gaffe. The left likes to make fun of how GWB pronounced the word “nuclear”, (which is just an accent BTW, like how some people say i-dear for idea, it is a product of where they grew up). But the way Obama says corpse-man twice in the same statement, shows he may not understand what the word. So which is a sign of intelligence?