Well...forgive me Umberto but I highly doubt this is a problem with the sound devices...
We'll check this, but it's the only thing that can be possibly have an effect like that one.
all looks good looking under Device Manager and I keep my PC very clean and optimized at all times
That doesn't mean much.We had another user that installed all the latest audio drivers, everything *appeared* to looks good on the Device Manager but, turned out to be the audio drivers WERE at fault, and the problem was fixed by uninstalling the "latest drivers" and restoring the one the comes with Windows because, apparently, the latest drivers suggested for his mainboard, didn't support OpenAL, which GSX needs to work.
And yes, he too didn't had the Couatl menu anymore.
and since I after the update no longer have the Couatl menu inside FSX I can't get to the GSX settings page...
Try to enable logging, open the Notepad and type the following on a new blank file:
logFile=couatl.log
(please note logFile is written beginning with a lower case l and a capital F )
Save the file as couatl.ini in the FSX\fsdreamteam\couatl folder, so it stays at the same level of the couatl.exe
Launch FSX, go to any airport, when it finished loading, exit from FSX, check if you have a Couatl.log file in the fsdreamteam\Couatl folder, and post its content here. Be sure Couatl.exe process isn't already running. If it is, terminate it with the Task manager, and then start FSX.