Linked user name Wiki tag crashes Confluence

When I created my Confluence account I used my email address as my user name. I'm starting to regret that because it makes the URL for my profile very ugly. Anyway, when I put the following into a Confluence page:

Andy.Armstrong@pantero.com

I got a null pointer exception in Confluence (see attached error page). Is this the wrong way to be doing this? Either way it shouldn't crash, because from then on the only way I could seem to make Confluence happy again was to delete the whole page.