Having some more possibilities to debug cache block behavior would be nice. I suggest adding conditional debug statements (identifier: eztemplate-cache) to the eztemplatecachefunction class.

One of the things that should be displayed is the unique string based on the cache block placement and the passed cache block keys, as well as the final path to the cache file to be loaded. Also information about the expiry check should be displayed.

Example attached as a patch for the trunk.