Dialogue box about opening score produced in older version appears in every open attempt

1. Download attached score.
2. Double-click score to open.

Result: Dialogue box 'Unable to open score reliably: It was last saved with 0.9.5 or older. You can convert this score by opening and then saving with MuseScore version 1.x' appears.

3. Double-click it again.
4. 'OK'.

Expected result: Regardless of clicks, the dialogue box appears only once (to be then clicked away).
Actual result: The dialogue box appears for every time the score is opened - twice, in this case.

Using MuseScore 2.0 Nightly Build (5499) - Mac 10.7.3.