realpath failed to canonicalize

I continuously received the following two errors when using this module. I'm using 4.7 and running APC 3.0.13. It seems to be APC that it's crashing with because adding a filter (removing amazon.module) fixes the issue from an error log full of these. These two lines fill up my apache error_log file.

realpath failed to canonicalize amazon.php5.inc - bailing
realpath failed to canonicalize amazon_init.inc - bailing

Using apc.filters = amazon fixed the error from being generated.

I'd have no idea how to start troubleshooting this one.