You have been taking the Required Minimum Distribution for a while, then your bank forgets (or you forget) to the the RMD in a year. The IRS will penalize you 50% of the RMD unless you do the following:
Take the RMD the following year (There will be two RMDs that year) and
Request a waiver of the RMD penalty with your tax return,
See the IRS website for more info:
http://www.irs.gov/retirement/article/0,,id=96989,00.html#9
I can help with this – call me at 818-317-6035 or email me at bstonercpa@sbcglobal.net with questions.You can count on us to count for you!