Only a core set of attributes are added to the product collection (for the list page) by default. This bit of XML will allow you to add additional attributes to that collection:
<config>
<frontend>
<product>
<collection>
<attributes>
<some_attribute/>
</attributes>
</collection>
</product>
</frontend>
</config>
Posted by Mike Whitby to Magento (2013-07-31 08:01)