slur from first note of measures causes previous measure to break mm rest

Windows 7, GIT commit: 47cd803

1) open attached score
2) verify first four bars are empty in both flute and oboe parts
3) view flute part, observe 4-bar mm rest
4) oboe part, observe 3-bar mm rest plus one bar normal rest

This is not right - oboe part should also show four bar mm rest. Turns out it';s the slut that is causing the problem, as can be verified:

5) select slur in oboe part
6) delete

Result: mm rest becomes 4-bar as it should have been all along

There are also issues with slurs not saving in some cases - it took a couple of tries to save this score - but I don't have good steps to reproduce this.