I had a client who sold her rental house in 2004 and decided she didn't need me to do her 2005 taxes because "they are so simple". She had a W-2, interest income and dividend income. She ended up paying about $1000 in additional taxes.
For 2006 she sold some stock and decided this "was not so simple" and dropped off her stuff. I asked her to drop off her copy of what she filed in 2005 "because it was so simple". She did not take into account the qualified dividends of over $6000 and even forgot to take her exclusion. I'll be getting her about $1200 plus interest back. She vows never to do her own return again.
taxbilly