Hello Chris,
Did you finally solved the problem ?
I think that we are a lot to have this problem but still unable to find an answer.
Here is a resume of the problem (for me and I guess most of you guys) :
Here are the softwares on Windows7 who read well the footage with a good gamma :
windows media player
Internet explorer
Flash player
Adobe programs
Here are the softwares that read the file with a wrong gamma :
Vlc
Vimeo on chrome and firefox
Quicktime 7
Is there some guy here who could finally solve this problem which is driving us mad ?