I'm experiencing very unusual behavior in my FSX installations. Yesterday everything went beautifully, all sounds were present. Today, I found my copy of the CV-580 for FSX had no engine sounds - yet every other sound (i.e., switch clicks) was working fine - as was the GPU sound. Just for fun I tried the default powered glider and its sounds were muted as well.

I've made sure my "Q" key setting (FS mute function) was not set to "on." I've also checked my sound configuration in the affected sim, and I haven't muted anything by accident, nor run it down to the bottom of the scale. The speakers are fine. I can get music via YouTube, plus talking heads on news sites.

This can't be a problem with the drivers on my sound card, from what I can see. If it were, I wouldn't be having any luck with anything my computer could access, I'd be silent across the board, I would think - but I'm still getting proper sound functioning with everything except engine sounds for all aircraft, original or add-on. That also goes for original engine sounds, and add-on engine sounds.

I've done research through the archives but can't find anything that could duplicate this issue - though in a roughly related posting someone suggested pressing the "Q" key twice for another problem. Tried that, no soap. I've also never experienced this issue since I began flight simming in the early 90s.

Does anyone have any ideas about what issue this might be?