I released Geekbench 2.0.9 yesterday. Geekbench 2.0.9 features a new (proper!) install program for Windows, and high-resolution icons for Mac OS X Leopard and Windows Vista.
Geekbench 2.0.9 also uses a new serial number algorithm. The old algorithm was written in a couple of hours before the release of Geekbench 2.0.0, and as such it was incredibly easy to reverse engineer. Over the past few months several people have written utilities that generate serial numbers that appear valid.
There will always be people who won't (or can't) pay for software, and trying to stop them from circumventing copy protection mechanisms is practically impossible. Also, time spent working on these protection mechanisms (like serial number algorithms) is time not spent on adding features or fixing bugs in Geekbench.
However, there comes a point where the tools used to circumvent the copy protection mechanisms become so widespread that they're starting to hurt sales. So, that's why there's a new serial number algorithm in Geekbench 2.0.9.
How will this affect you? If you purchased Geekbench before the new serial number algorithm was released, your current serial number will continue to work in Geekbench. If you purchase Geekbench after the new algorithm was released, your serial number will only work in Geekbench 2.0.9 and later.
I really hope the change to a new algorithm is as painless as possible for most users, but I wanted to talk about it so that it's as transparent as possible, too.