[trunk] Tempo indications are inactive

Setup: rev. 4712; Ubuntu 11.04, Qt SDK 1.1 (Qt lib 4.7.3)

Steps:
1) Open a score with some tempo indications: a simple test score created with rev. 4712 is attached.
2) Play the score back.

Result:
The score is played at a fixed tempo (100-120 MM ca.), regardless of any initial and/or mid-score tempo indication.

Note: When the score is initially created, the tempo indications are (always?) put into effect by playback, but after saving and reloading the score, they are disregarded.

M.