I just had a thought, when I flew to Dubai in 2009 I made sure my hold-baggage e-liquid was in sealed unopened bottles and packaging, A small 10ml opened bottle, mod, atomisers, batteries in plastic case with contacts covered in electrical tape plus charger went in carry-on luggage. E-cigs weren't too well known then, so I took no chances.
Perhaps its a non-issue, but for people who mix their own juice (as I do nowadays) would unlabelled bottles of liquid cause any issues? - I mean it could be anything in there.