The TVPaint Wiki explains that the tv_FrameRate GEORGE command was apparently modified as of version 10.0.10. I think there was a bug introduced.
Example, George command tv_FrameRate 10 changes the frame rate to 10... but also scales (zooms) the project window to 150.63%.
FIX: George command tv_FrameRate 10 INFO just changes the frame rate to 10 (but the new version should work as expected without the INFO parameter, shouldn't it?)