The concern for FHA is when a consumer applies for credit and indicates it will be a primary residence when in fact the purpose of the purchase is to acquire a rental property. I don't see an occupancy issue from what you have described.
If you had purchased the property as a primary residence and kept the property as a rental property instead, that would be where you would run into trouble.
Good luck selling your home.
Given the current number of foreclosures lenders are dealing with it would be really unlikely that they foreclose due to a change in occupancy. From a lenders perspective they are better off keeping a performing loan rather than foreclosing becuase of a change like that.
Best of luck.
Its one of those things that you just do the best you can at the time. when you signed the FHA doc's your intentions were one way, and things change. Just be careful, and be completely truthful with both lenders at all times. Good luck.