ok so here's what happened.

Whilst at the duty free I purchased a nice little box of cubans, totally unaware that I was unable to bring them into the country.

I then arrived at IAD, and as soon as I cleared customs I decided to transfer them into my checked luggage instead of putting them through my x-rayed hand luggage, purely as a weight saving measure you understand.

However, when I arrived at my destination my suitcase hadn't. Into the lost luggage offce, I was told that my luggage had been detained at IAD. Cue anal winking. After establishing that it wasn't anything to do with contents and was just an airline screw up I relaxed and started spending the insurance money. The next day the suitcase arrived, contents intact.