changing omitNorms on an already built index

[Jonathan Rochkind]

So Solr 1.4.  I decided I wanted to change a field to have 
omitNorms=true that didn't previously.

So I changed the schema to have omitNorms=true.  And I reindexed all 
documents.

But it seems to have had absolutely no effect. All relevancy rankings 
seem to be the same.

Now, I could have a mistake somewhere else, maybe I didn't do what I 
thought.

But I'm wondering if there are any known issues related to this, is 
there something special you have to do to change a field from 
omitNorms=false to omitNorms=true on an already built index?  Other than 
re-indexing everything?    Any known issues relevant here?

Thanks for any help,

Jonathan