I had the same problem with Opera 10.50's title bar getting messed up when running WB7 and found a solution using the 'Opera Launcher' at this web site. http://my.opera.com/Tamil/blog/opera-launcher
It launches Opera and fixes the title bar problem and backs up a bunch of the opera files at the same time (bookmarks, contacts, etc.)
Hope this helps.
EDIT: OperaLauncher lets you disable the title bar. When you do, the min/max/exit buttons are no longer displayed. I guess you exit Opera using the menu or the 'big O'.
EDIT: April 3,2010 --- This 'fix' no longer works with the latest beta release of Opera. It worked in Opera 10.52.3337 but no longer works in 10.52.3344.