I experienced this bug (http://www.simplemachines.org/community/index.php?topic=60925.0) reported by ShaneR and confirmed by archiebald.
I believe it's caused because there are weird characters in the names of some of the variables in the form.
Hopefully this will be fixed in the final 1.1 version.
Meanwhile, I changed the forum title manually editing Settings.php
The cause of this issue is shown here:
http://www.simplemachines.org/community/index.php?topic=60925.0