qVamps: Menu video encoding fails due to missing mpeg2enc
If this happens even though you have the MJPEG Tools installed, your Linux distribution uses a somehow crippled MJPEG package. The original MJPEG definitely comes with mpeg2enc. You either have to find a full version of the package or use the sample background MPEG that comes with qVamps >=V0.18 (penguin_ntsc.mpg and penguin_pal.mpg). Please note that you have to switch the file type in the menu background selection box to "DVD Program Streams".
ERR: procremap encountered unknown subtitle command: 7
This is a problem with dvdauthor, which occurs with some subtitle streams. Either try to deselect some subtitles or try to apply this patch against dvdauthor-0.6.12-alpha-2992 and reinstall from the modified source. The patch may also work if applied against other versions of dvdauthor, but this has not been tested.