Flap sounds last longer than movement

Hi all,Strange problem this one. When I extend the flaps on the PMDG737-700 the flap sound lasts longer than the flap movement. To be a bit more precise...Setting flap 1 from flaps up. Sound is about 1 second longer than movement.Setting flap 2. Can't see any visible flap movement (leading or trailing) when flap sound plays. One 6-second sound is played followed by a short pause of 1 second followed by a second sound about 1 second long.Setting flap 5. Flap movement lasts 2-3 seconds. Sound lasts 5 seconds.Setting flap 10. Flap movement lasts 2-3 secs. Sound lasts 5 seconds but is repeated a further two times in quick succession.Setting flap 15. Movement and sound lasts about 3 seconds.Setting flap 25. Movement and sound lasts about 5 seconds.Setting flap 30. Movement and sound lasts about 2 seconds.Setting flap 25. Movement and sound lasts about 5 seconds.I have four flap sections in the aircraft.cfg - Flaps.0, Flaps.1, Flaps.2 and Flaps.3. The extending-time setting in each is as follows: -20, 20, 7, 7.5. The defaults are 35, 35, 25, 7.5.Reverting to the default times make the problem even worse with multiple sounds being played for each flap change.Is there a logical way to calculate how long the extending-time value should be set to for each flap section?Thanks,