Thanks LTN Phobia, the one I have been using is 90W. It always works with aircraft without the new Thales IFE. BA says that the socket power is limited to a maximum of 100 or 125 watts depending on the system. Apparently this is becoming a common problem, including the new 78 fleet. It becomes a real problem if it is not possible to work on a daytime flight, which one of my regular flights BKK-LHR is becoming!