The is a new setting for the Alpha Sorter ...

At the moment there is a bug to it that when set off, it turns off the manufacturers' dropdown ... or the Categories dropdown ... when the Alpha Sorter is turned off ...

This is in the Configuration ... Product Listing ...
Include Product Listing Alpha Sorter Dropdown
Do you want to include an Alpha Filter dropdown on the Product Listing?

true
false
I also have a temp fix for this posted at:
http://www.zen-cart.com/forum/showth...t=alpha+filter

The actual fix is more specific, but this can work for now in lieu of v1.3.8 release ...