It's not normal that reinstalling the Stand-Alone Addon Manager would "fix" any Couatl crashes, because it will just reinstall the same set of files.
However, what the installer also does, is to reset some settings you might have changed in the wrong way, or some other 3rd party app might have wrongly set, like any of the Compatibility modes for the simulator executable (it shouldn't be set, which is how the sim is installed by default), and it will remove some tweaks in the FSX.CFG which are known to be dangerous, such as the Poolsize set to 0.
That would explain why you think Couatl was the cause, when the problem where the wrong settings, and why launching the installer again seemed to fix, until you or some other product re-set the settings wrong again.
