Recent changes in QTV that add more functionality (cmd lastscores at last!) will also require updated binaries of MVDSV and KTX. Revisions that are compatible and fully supporting QTV are:
QTV rev. 56
KTX rev. 728
MVDSV rev. 769
Don't panic; earlier revisions will still work but they are just missing some of the features so nothing will get broken even if you can't match these revisions (or later ones).