extra characters here too

I just switched to Vista and am also noticing the extra letters, like "patientt" or "wiill" happening sporadically. I tried to switch to Shorthand but I was as slow as a snail, so I really want IT to work. Spellcheck will usually catch these, but I did have one word today that had an extra letters and it wasn't misspelled! I can't remember which word it was now...