Beta 9 was using synchronous network I/O. Beta 11 has asynchronous I/O. Apparently when doing an asynchronous connect Java will call getsockname() before the connection is established. This works on every operating system except Windows 8.
Are you using the latest, Java 7, update 4?
This could become an annoying issue. There's no workaround either.
Yes i have Java 7 update 4.
Guess i have to use the non Beta Miner. If there is no workaround you might want to consider an option to switch back to synchronous networking.
Let's hope the final version of Windows 8 or the next Java update fixes it.