[PPC] Lubuntu 12.04 PPC on iMac G5, black screen with cursor

Hi,

I'm booting off a usb drive with the option "live b43.blacklist=yes" (else I get stuck at the message, isight failed loading firmware).

I get past the splash screen up to the point where I can move the mouse cursor (very sluggish) on a black background but can't get anywhere else, not even ctrl+alt+F1.

I tried radeon.modeset=0 video=radeonfb:1024x768-24@60 noveau.noaccel=1 with no difference (It's a X600 with RV380 chip).

Any advice very welcome!

Thanks!