Got a letter (4 actually) from Memphis IRS assessing interest and penalty for underpaying 2007 estimates. The thing is, I sent in a
2210 with my return, but the letter makes no reference to it. I looked at the interest they figured, and it appears to be based on using the "regular method" to figure estimates. On my 2210 I checked the "annualized income method" box and completed the appropriate AI section. So I wrote a cover letter explaining and included a copy of my 2210 and sent to the reply address on the notice. But I'm wondering if I should do something more pro- active?scott s. ..