I just started having the same yellow tack / corrrect symbols switching back and forth.
After playing around and taking a chance, I downloaded the newest KML. Openned it in Google Earth. The new version showed up in the Places section under the temporary places folder. I had an existing "Geocaching Network KML" under the My places folder. I delted the My places one, and moved the one from the Temporary places up o my places and no more yellow tacks, just the cache type icon. Good luck!