MusicXML import looses a staff
Trying to import a piece of music for TTBB + 2 pianos, with 6 staves (TT, BB, P1, P1, P2, P2), the 5th staff doesn't get imported, and I end up with only 5 staves, missing the right hand of the 2nd piano. The notes appear to attach themselves to the 4th staff (P1 left hand) instead. It also groups the 1st 2 staves and labels them jointly as "Tenor". Notation correctly imports the identical MusicXML file. The file is from Sibelius 7 via the Dolet 6.2 plugin (although native export misbehaves identically).