Link Expires saying "UNLIMITED"?

I have downloadable URL's set up for all my MP3 files. I use the default number of days and downloads allowed from the config/attributes of 7 and 5 respectively within each MP3's attributes. However when a purchase is successful, the user's Thank You screen is provided with link expires stating unlimited, and remaining = ***. Is there a setting I am missing that will return the actual number of days and download values I have set? My version info is..

Zen Cart 1.3.8a
Database Patch Level: 1.3.8
v1.3.8 [2009-07-19 16:55:22] (Fresh Installation)

PHP Version 5.2.12