Network interfaces problem

Hi,

I have problems with my SCO unix network interfaces.
Intel integrated adapter was failing, so I installed new one - 3COM adapter into free PCI slot.
Installed driver using SCO Software manager - successfully
Added new Network adapter using SCO Network configuration manager - successfully
after that I checked using ifconfig -a
there was some loopback interfaces and - net0 -intel interface, and net1 -3com interface.
So I thought that everything is OK and removed intel adapter using Network configuration manager, after that things went wrong:
ifconfig -a displays only loopback interfaces.
3com driver is installed, 3com network adapter is added(Network configuration manager), but ifconfig -a don't display it!!!

So I thought that it's hardware problem - booted knoppix from cd - my 3com adapter is autodetected, up and running!

After that I tried all 'dumb' ways - rebooted, reinstalled(driver), changed apapter pci slot...- result is the same -driver - OK, adapter(Network configuration manager) - OK, "ifconfig -a" - no entries. By the way devices net0 and net1 are present(I asume net1 is my 3com adapter).

I'm newbe in unix so maybe I missing some 'obvious' step ?
How to force my 3com adapter(net1 ?) to apear in ifconfig list, and force it function corectlly ?

thank you
Vilius