It's not actually caching - View Source on the main post page (not inside the iframe). The source for the inner iframe is contained on the post page, the document.write is used to write it into the iframe. Quite spiffy - we found it is much faster than a new request.
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com