Did you see that the winner was asked to spell a word in the preliminary round and he thought he heard (it did sound like it) 'numbnut'? He was embarrassed to spell it and asked for a repeat. Fortunately the announcer defined it and the contestant said "Oh, numdah". Very calm young man!
http://dictionary.reference.com/search?r=2&q=numdah
As far as spell check goes - I try to use it for every post but sometimes we all use words that are spelled correctly but misused such as "their", "there" or "too" and "to". Spell check also has some faults. The following word is misspelled but for some reason passes the test: "televesion". Go figure!