I try to use the current name of the organic group in the page title.
Using the module pagetitle I set the title for one new page type like this:

Termin [node:title] [node:group_audience] | [site:name]

But I get a title with (a)Groupname(/a) in the text.

I think this is either an error or works in an unexpected way. The other tokens get replaced by their plain text as expected.