Upgraded to 3.2 now can't get into site at all

Please help, you have all been so helpful before.

I just upgraded to the latest WP version and now can not get into my site at all. Here’s the error that I get:

Fatal error: Call to undefined method Arras_Widget_Tag_Cloud::WP_Widget_Tag_Cloud() in /hermes/bosweb/web091/b914/ipw.obsessed-with-music/public_html/wp/wp-content/themes/arras/library/widgets.php on line 404

It is the Arras theme, thinking maybe it is a problem with the tag cloud plugin but can’t get in to disable it to find out. Help!! **please**