Restoring from backup made by WP-DB-Backup 2.1.5 was nothing but grief. The backup file first introduces funny characters of "0xC2" see http://ywywy.com/q/2007/10/10/funny-characters-after-restoring-from-a-wordpress-backup/ . Secondly, Counterize II 2.10 tables could not be restored properly. Thirdly, it took so long to back up my database, over a minutes with almost 100% CPU (P4 3GHz) for a few hundred KB.
The problem was that WP-DB-Backup doesn't use the standard mysqldump utility but resorting to PHP code. I'd recommend WP-DBManager 2.20 by Lester ‘GaMerZ’ Chan.