Early Distribution Penalty on an RMD from an inherited Ira

I have had an Inherited/Beneficiary  IRA for the past 8 years and each year Raymond James sends me a check for the RMD. This year when entering this into Turbo Tax they are saying I own a 10% penalty for an "early distribution" from a retirement plan or IRA. Nearly certain I have answered all the question correctly (e.g. was this IRA inherited?). I am 55 and the original account owner was born in 1936.  Any ideas why this is occurring?