I think I may have found an answer to this problem. Seems much of the a4j: tags are 'broken' in IE9. There is an entry here: https://issues.jboss.org/browse/RF-9485 that is related. I applied the patch noted there (overwrite AJAX.js into appropriate richfaces-impl jar) and the prolem I was having with IE9 and a4j: tags seem to be resolved.
In that jira entry, I know Nick indicated it wouldn't be fixed in RF 3, but to make things easier for folks that need to remain on 3 for awhile - is there any possibility of making this an "official" update to richfaces and releasing as, say richfaces-3.3.4? I assume this update to the demo pages would also resolve the issues stated above.