Comment 70 for bug 562742

So the low 4 bytes of the MAC address get zero'd on warm reboot for some
reason.
2.6.32 writes the MAC address to the card on shutdown. It calls rtl_rar_set()
which does:
...
        RTL_W32(MAC0, low);
        RTL_W32(MAC4, high);
...

And the card loses the 'low' part. Wild guess - perhaps the card wants to have
the high half written first.

Anyway, the writing of the MAC address on shutdown was introduced by the
commit:

commit cc098dc705895f6b0109b7e8e026ac2b8ae1c0a1
Author: Ivan Vecera
Date: Sun Nov 29 23:12:52 2009 -0800

    r8169: restore mac addr in rtl8169_remove_one and rtl_shutdown

Gavin, could you test if reverting the commit would fix your problem?

Putting Ivan to CC... Ivan, any ideas?