DUB as in Dubai....
Just for your information, Dubai is DXB
As far as the KLM 777 in Houston. It is possible, but highly unlikely. MD
-11 sounds more reasonable, but surprising none the less. IAH
is a big cargo market so I would imagine KLM makes quite a bit of money on the 747 Combi aircraft. Re-positioning a non Combi plane would really make things difficult for them I would imagine. Though KLM has been doing a lot of substitutions lately, DEL is one example. It is suppose to be a combi but hardly gets any these days, its mostly been a full 743 pax configured aircraft.