fuel cock won't budge

[Desertowl]

hello all,

i'm trying to start up the spit IIA in CEM, for some reason the fuel cock won't move from the off position.
i tried to assign it to a key, move it with the mouse, use the force on it - but nada.
i'm playing with the stock version, no beta patch installed.
btw - this happens with other variants of the spit as well...

am i missing something here? any advice would be welcome.