1. Visit the official Zen Cart home page at www.zen-cart.com.
2. From the home page click on the Community Forum link in the top right hand corner.
   
3. Scroll down the main forum page to the section Upgrading your Zen Cart.  Click on Upgrading from 1.3.x to 1.3.8.
    
4. At the top of the threads in this section is a ‘sticky’ thread titled Known Bugs (and fixes) with v1.3.8 / v1.3.8a.  Click on the title. 
   
5. From the Thread Tools menu, select Subscribe to this Thread.
6. There are a couple of options to choose.  Under the Notification Type menu, select from No email notification, Instant notification by email, Daily updates by email and Weekly updates by email.

   For most people, you can leave the setting for Folder as the default.

   Click on the Add Subscription button.
    

7. You will now be notified of Bug Fixes for your Zen Cart store as they are released.  

More Zen Cart:

1. Apply Known Bug Fixes
2. Using the Zen Cart Community Support Forum