Think about it. Compare the number of beta testers to the number of end users. That small dedicated sample is very statistically unlikely to find everything that can be found in the entire user community. There in lies a glory of the Internet. A new problem and a fix in 5 hours. Imagine, a product with out a feedback and fixable download ability. That problem wouldn't have been reported or solved for months. If you want perfection, get a set of legos. Even Microsoft has monthly patches to fix newly discovered problems. It's software, not a coffee pot.