Hi,
I am having exactly the same issue, my downloads gets corrupted after downloading. I've gone through all of the steps mentioned in this post but its still there, I am running:
Zen Cart 1.3.7.1
Database Patch Level: 1.3.7
Server Host: localhost
Database Host: localhost
Server OS: Windows 2003
Database: MySQL 4.1.14-nt
PHP Version: 5.0.4 (Zend: 2.0.4-dev)
HTTP Server: Microsoft-IIS/6.0
Please note, All of files are in ZIP format and no spaces or special characters in the directory or file names. Size is under 1 MB
Really appreciate your help
thanks