I had the issue on Mac OSX where the launcher would crash while launching, then after that issue was fixed it was upside down, now it is working and I made a video that MIGHT help others, feel free to check it out as I know these issues are really annoying!
http://youtu.be/rlRcjen_dv8
P.S. I know this is the Tekkit modpack forum and the video is for Voltz but it should work the same.
Good Luck! -Battelman2