Node repository tree problem


I'm undertaking some refactoring of our KNIME nodes and have changed the grouping in the node repository. This all looks fine when debugging but once I've built the update site and installed into a KNIME product all of my nodes are now in the 'Uncategorized' section. 

Is there a common gotcha here? 

I have the same extension points declared in multiple plugins (like before though). 



There appeared to be a conflict between two plugins providing a slightly different version of the top level extension point.