Netbook Pro - goes to black screen after boot.

After flashing the OS to the 404 version, when my NBP reboots, it shows the splash screen with the loading bar, and then nothing but a black screen.

Esc-CTL-D has no effect.

I assumed I had turned it into a brick - but learning of the linux versions out there has me wanting to try to get this working again.

Anyone have any advice on what else to try.
I've also tried putting the OS images on the SD card to try to re-flash the OS, but it doesn't seem to have any effect (so I need to use the CF card instead?)

Thanks,
Steve T.