You don't see this too often: a petition for panel rehearing that's granted (1) even though the initial opinion was unanimous, and (2) over a full year after the panel's opinion was published. The panel consists of Judge Beezer, Judge Fisher, and District Judge England. The original opinion is at 364 F.3d 1154, and was issued on April 20, 2004. Weird.
I guess we'll have to wait until the panel issues a revised opinion -- which it hasn't done yet, which is also weird, since the Ninth Circuit often withdraws and issues a revised opinion on the same day, especially when (as here) it doesn't allow additional briefing -- to see what's up.