I eventually had to remove mine.  It would work for awhile and then 
networking would die.  The MAC address seemed to keep changing.  I put a 
different flavor of 3c905 in and it's been working OK.

At 11:49 PM 5/9/2001 +0200, Urban Boquist wrote:
>Hi all,
>
>I have a 3c905C NIC which seems to have some problems getting the
>correct MAC address. Here is a couple of boots:
>
>groda# grep MAC /var/log/rtty/lan-gw
>ex0: MAC address 00:04:76:26:a1:0b
>ex0: MAC address 00:00:ad:ad:00:00
>ex0: MAC address 00:00:ad:ad:00:00
>ex0: MAC address 00:00:ad:ad:00:00
>ex0: MAC address 00:00:00:00:00:00
>ex0: MAC address 00:00:00:00:00:00
>ex0: MAC address 00:04:76:26:a1:0b
>ex0: MAC address ad:ad:ad:ad:00:00
>ex0: MAC address 00:04:76:26:a1:0b
>ex0: MAC address 00:04:76:26:a1:0b
>
>The card works Just Fine when it gets the "00:04:76:26:a1:0b" address,
>but not at all with the others (surprise ;).
>
>The card identifies itself as (NetBSD/i386-1.5.1_BETA):
>
>ex0 at pci0 dev 18 function 0: 3Com 3c905C-TX 10/100 Ethernet with mngmt 
>(rev. 0x78)
>ex0: interrupting at irq 11
>ex0: MAC address 00:04:76:26:a1:0b
>exphy0 at ex0 phy 24: 3Com internal media interface
>exphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
>
>Any thoughts?
>
>Regards,
>
>         -- Urban