Zen Cart version 1.3.7
Logon as admin, configuration, layout settings, category/products display order:
Is that a typo on option six? Should there be a - (minus) instead of a + ?
Categories/Products Display Sort Order
0= Categories/Products Sort Order/Name
1= Categories/Products Name
2= Products Model
3= Products Qty+, Products Name
4= Products Qty-, Products Name
5= Products Price+, Products Name
6= Products Price+, Products Name
Thought I'd bring it to your attention just in case both options 5 and 6 sort it +.