Vegas Pro 11 Chroma key problem

Greetings all. I just tried some basic chroma keying in pro 11, have previously done well with it in 10, but now no matter what I do, the subject, (part of the image I'm NOT trying to key out) turns a dark blue, purple color. The exact same project in pro 10 works fine. I even matched the RGB values precisely. My sister is normal color in pro 10 with background gone, in pro 11 she looks like the na'avi in AVATAR. Help!