several more recent ethernet drivers implement the ethtool interface found at http://sourceforge.net/projects/gkernel/ .
Since ethtool is not currently included, there's no way to modify things like speed and duplex of some of these ethernet cards even though they are recognized and the modules are correctly loaded.

I use the tg3.o driver currently, for example. there is no way with modprobe (or insmod) to modify these module parameters as there used to be in the past with older ethernet kernel modules. Apparently ethtool is the cool new way to do that. ethtool is available as a debian package (of course!)

thanx in advance for considering this.