Although there are strange goings on with the sounds on the C-130, I continue to use them the way they are installed, so that means I have accepted all the gauges that FSX has asked me to, for all the different C-130's - I have the C-130 X-perience (All-in-One Pack).

You might try installing the C-130 but not the sound pack that installs at the end of the installation. Doing that made no difference to the way the sounds get messed up, nor the performance of the C-130's.

I assume you install it using "Run as administrator".