Sorry, your PC operating system is not supported. Please get access to either a Windows (XP or newer) or Linux computer to install emCORE.
And as far as I know some Macs have difficulties recognizing a Rockboxed Classic on USB, perhaps because it is still being approached as a normal iPod instead of a mass storage device.
But I could be wrong here, there are not so many OSX users in this topic. I'm still curious if something like Wine would work here..
The latest daily Rockbox (f580714) is still working fine. However, there is a bug: after connecting through USB to a pc, it will always spin up the disk when you press any key, making it relatively slow and unresponsive. Rebooting solves this everytime, first boot after connecting USB there's always the message "scanning disk", after that it's fine until the next time you connect through USB ;-)