I don't find a 1009.5 beta bios, but I just tried the 1009.004 and 1009.006 betas (I've been using the 1008).
With the 1008, I can run my 3000 Winnie at 240FSB easily, at stock settings. With the betas, I couldn't get a POST at 220....I didn't try lower than that. So I'm back to the 1008, and running 240FSB again.
JC