Comment 1 for bug 876312

I'm affected by this bug and here is what I found while digging around.

1. It seems that the underlying magento bug is fixed in magento >= 1.4.2. Unfortunately, I'm stuck with 1.4.0.1.

2. People have found a local fix, eg on http://magja.googlecode.com/svn-history/r417/trunk/src/main/java/com/google/code/magja/model/category/Category.java, there is the following doc string for setAvailableSortBy

Run this SQL query first to fix the available_sort_by bug (tested with Magento 1.4)
            <code>update eav_attribute set is_required = 0 where attribute_code = 'available_sort_by';</code>
See:
           http://www.magentocommerce.com/bug-tracking/issue?issue=6842
           http://www.magentocommerce.com/boards/viewthread/48088/#t198697

3. if accessing the magento DB is not possible, then a safer way is to pass an empty string, which is processed by Magento as meaning "use all categories". This also works for the default_sort_by attribute (in which case Magento interprets this as 'use the parameters of the configuration'. In any case, passing the string "None" (which is the current behavior of the connector) is a bug. Empty string is what must be passed.