Here's a classic fail for you:
Finished some lovely new sounds. Great sounding exhaust, giving that real spine-tinging sound when an engine is really opened up! So, I go into the game to test this all out. I used the short whistle sound, assigned to the B key - lovely. This has signalled my pull away. Having released the brakes, I crack open the regulator. Nice and easy pull away, then I wind the reverser and open up into second valve. Oooooh yes, this is sounding good!! So, it seems right and proper to blow a nice long whistle in celebration. And this is what I did. However, the sound which came out of the whistle wasn't a lovely BR Standard whistle, as it should have been. Oh no! The sound that accompanied the masses of steam coming from the whistle was a guards whistle!!! I just wish I was filming at the time!