The old browser was becoming difficult and inefficient for Opera to keep current. It wasn't "fixed", it was redesigned from the bottom up. Some things that might have been possible with the old design may now be much harder to do, while other things needed to keep the browser "current" with web developments may be much easier to do. Moreover, at the same time, Opera redirected its market-segment targeting away from techno-users. Like it or not, that's the way it is: the decisions were taken, the money's been spent, the personnel reassigned, and the company's headed down its new path (going on nearly 2 years now!).