Flipping stems of manually moved cross-staff beam don't initially draw correctly

1. Open attached score (produced in 1.3).
2. Double-click the beam.
3. Drag the left handle down.
4. Click somewhere to disable 'edit mode'.

Result: The stems are on the wrong side of the stem.

Notes:

Actions, such as 'Select All', draw them correctly.
It only seems reproducible in a 2.0 score if dragging the handle upwards.

Using MuseScore 2.0 Nightly Build 83622b0 - Mac 10.7.5.