Dr,
It is hard to get a straight answer. In November 2002, I flew from ATL to London Gatwick on Delta and back from LGW to CLT on US Air. Last month I called US Air reservations and asked if there were any problems jumpseating Internationally, and they indicated that it is still "OK". I jumpseated over on Delta (again ATL-LGW). After several days in the pub, I tried to jumpseat back on US Air and the girls behind the desk said that there are no more Int'l jumpseat priveleges offline. I frantically ran to the Contintal desk and they gave me a ride to EWR. About a week later, I was killing time in CLT and went to the "D" terminal and walked up to the US Air rep at the Frankfurt desk, to ask the int'l jumpseat policy, she said it was up to the captain of that flight. Best of luck