The IRS sent me a bill in September for $4000 saying I didn't report $25,000 worth of income in the year 2003. This was probably an error on the part of me and Turbo Tax, which I will probably not use anymore. Apparently there was a misunderstanding about the stock options I get from work. The company graciously "buys" the options for me at a lower price and then I sell at the price I like, pay back the company, and keep the difference. The IRS seemed to think ALL the money from selling was "income," which I can assure you it is not. Additionally, any profit I make is taxed at about 40% and immediately reported on my W4 or W2 taxforms.
Sure, the IRS took two years to bring the issue to task and sent all the information to the wrong address, but ultimately I only had to contact them once to clear it up. I just got a letter today saying "Everything's cool." That probably doesn't sound that impressive but you should try communicating with a "Flexible Spending" provider. What a scam. In comparison, the IRS was highly effective. I'm just glad they don't want to fight. I bet you thought talking about taxes wouldn't be fun.