DIH and rss feeds

[Lance Norskog]

I have a DataImportHandler configured to index from an RSS feed. It is a
"latest stuff" feed. It reads the feed and indexes the 100 documents
harvested from the feed. So far, works great.
 
Now: a few hours later there are a different 100 "lastest" documents. How do
I add those to the index so I will have 200 documents?  'full-import' throws
away the first 100. 'delta-import' is not implemented. What is the special
trick here?  I'm using the Solr-1.3.0 release.
 
Thanks,
 
Lance Norskog