Hi,
For some reason the driver is failing to load, but this is the most up-to-date driver available for BC (ver 10.03).
Could you try creating a floppy and try to boot with it - just to make sure that the PXE boot does not interfere with the driver?
Could you try selecting 'PXE packet driver' instead of BC driver when creating the RIS boot image (I am not sure if it is available in 8.0 under RIS though - please check - we started providing that driver for non-3Com PXE images from 8.3)
Krish