Can't change tie direction

ties are not detected as such in Inspector, but as plain elements, with the consequence that you can't change their direction using the Inspector ot the X shortcut. (you can by using edit moe and moving ther appropriate handle)
Changed directions from 2.0 score get lost (→major) and a debug message shows up:Debug: tie-volta: xml unknown tag at line 927 col 18: up (...\MuseScore\libmscore\xml.cpp:191, void Ms::XmlReader::unknown())

self-built b7a53fc, Windows 7