A lot of people prolly didn't and won't unless they read the comments, Laura. Our eyes and brains usually follow patterns and when something seems familiar to us, even when there's some slight rearrangement, we read or see it the way we've gotten used to reading and seeing it.
I'd imagine that's a reason why when one's doing a serious bit of writing that a good spell-check and a proof-reader are necessities. Also why even the proof-readers, multiple ones, miss things and you find them in your favorite novel on page 210!