If I understand correctly, tulip and dmfe conflict, so when you modprobe dmfe, tulip isn't reloaded?
You can blacklist tulip to prevent it from loading. List "tulip" in the file: /etc/hotplug/blacklist and it won't be loaded by hotplug when you reboot. If you are using udev instead of hotplug, list "tulip" in /etc/modprobe.d/blacklist to prevent it from loading.
If the above isn't the problem and there is something weird about removing and reloading both
modules, you can automatically run the commands you are using during boot up as a work around. Edit the file /etc/rcS.d/S40networking. Just under where it says "Configuring netwrok interfaces...." add your commands: