In /styles/prosilver/template/posting_editor.html line 32 reads:
...in contrast to line 20 which reads:
The former (line 32) misses a nbsp in front of the <!-- ELSE -->.
Interestingly enough I fail to find the ability to add a group as BCC recipient in a vanilla installation. Discovered this by chance when modifying both the template and one of the UCP files to add a checkbox named "Add [BCC]" near the group box (which does what its named like).