Modify apachesolr's 'did you mean?' suggestions to provide better alternatives Has anyone modified the default apachesolr 'did you mean?' suggestions that is returned out of the box with the apachesolr module?

For instance, a search for 'diabetes' currently returns 'did you mean: rates' http://www.health.govt.nz/search/results/diabetes

Is there a way to add some form of control over this, or is the solution simply adding more nodes to the index in the hopes of making it a better spell checker?
I found setting:
&lt;str name="spellcheck.onlyMorePopular"&gt;false&lt;/str&gt;

(instead of true) in solrconfig.xml dramatically improved the quality of the spelling suggestions.