Adding filter to aggregated feed doesn't work

I've create an aggregated feed called 'JBoss Events' in the Events group:

http://planet.jboss.org

I'd like to add a Global Filter using the 'Add Filter' link from the 'Edit specific' page as follows:

Only entries where at least one category matches a regular expression: jbug|workshop|conference

However when I click on the Add button nothing appears to be done. Looking at the aggregated blog still shows all the posts:

http://planet.jboss.org/view/feed.seam?name=events&from=0

Please can this be fixed so we can aggregate blog posts from multiple people with the tags 'jbug' or 'workshop' or 'conference'.