When I run a fresh 6.0 EE SP1 tomcat and login as firstname.lastname@example.org/test, I add the activies portlet and the blog portlet. I add a blog and see that it shows in my activities. I click the "Subscribe to Joe Bloggs's activities. (Opens New Window) " and it shows:
Subscribe to Liferay's activities. 2011-01-25T23:02:13Z 2011-01-25T23:02:13Z 2011-01-25T23:02:13Z
I believe this is because the xml is starting with a space.