I’m playing around with my WordPress theme again — I really like the basics of this one (called Miniflex), but there are so many basic formatting problems I don’t think I can keep it. Any recommendations for similar style themes?
playing around with theme again
John's Blog 
I had faced similar problems in formatting flexible width themes. I found some very good themes at this page
http://wphacks.com/best-wordpress-3-column-themes/
Of course, you have to select what you like in appearance and functionality.