Comment on Blix AdSense WordPress Theme by SEO Dave.
Glad yo like the theme.
The title header problem was solved in the latest update when I added WordPress 2.5 compatibility (only free AdSense theme I updated on this site BTW, should work fine with WordPress 2.6.3 as well).
The Sidebar issue, I’d guess you’ve edited either the functions.php file or sidebar.php file and made a mistake (very easy to do).
Try uploading the original functions and sidebar files to see if it fixes the issue.