The copy of AROS thats under Windows is running in a PC emulator (it's a whole virtual PC!) that can't access your hardware directly, hence the NVidia mode doesn't work. The Vesa mode should be ok, and show whats what though ;-)
In the folder of WinAROS-Max the ISO file is the full 0.2.0 file, so burning it and booting it you might be able to use the NVidia mode (not sure about 6800 support, I know the definitions are getting an update soon though). It works nicely with GeForce cards :-)
MDMA - we've moved 14Gb of data in the last day!