I'm pretty sure I don't have failures on, but I will have to double check. As for not hearing an audible overspeed warning, do you think this could be part of the fact that 2.4 has the sound issues?

And out of curiousity, when you go into overspeed and don't make the necessary corrections, does FSX pop up the screen showing your aircraft with the green message at the top saying you've gone into overspeed? That is the screen I got and the only way out of it was to hit the ESC key which then took me back to KCVG. (of course you get the black screen where its loading, but then restarts your flight at the departure airport).