PCI ethernet card from ebay doesn't work at all. Possibly fake, but which?

["A. F. Cano" <afc@shibaya.lonestar.org>]

Hi,

I needed a PCI ethernet card for an old P3 system and so I did some
research to make sure it was supported and got the first
one that showed up on an ebay search.  At least it was cheap.  The
sellers all claim that they were RealTek (RTL8139D) and they are
detected as such.  This is what lshw says:

        *-network UNCLAIMED
             description: Ethernet controller
             product: RTL-8139/8139C/8139C+
             vendor: Realtek Semiconductor Co., Ltd.
             physical id: a
             bus info: pci@00:0a.0
             version: 10
             width: 32 bits
             clock: 33MHz
             capabilities: cap_list
             configuration: latency=64 maxlatency=64 mingnt=32
             resources: ioport:e400-e4ff iomemory:ec008000-ec0080ff irq:9

and lspci -v says this:

00:0a.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
	Subsystem: Realtek Semiconductor Co., Ltd. RT8139
	Flags: medium devsel, IRQ 9
	I/O ports at e400 [size=256]
	Memory at ec008000 (32-bit, non-prefetchable) [size=256]
	Expansion ROM at eb000000 [disabled] [size=128K]
	Capabilities: [50] Power Management version 2

And this is what is written on the chip:

RTL8139D
6312251
L622W
TAIWAN

There are no other brand name or markings on the circuit board.

The drivers the system loads automatically (8139cp and 8139too) generate
no errors, but doing ifup eth0 (either at boot time or manually) gives
this:

SIOCSIFADDR: No such device
eth0: ERROR while getting interface flags: No such device
SIOCSIFNETMASK: No such device
SIOCSIFBRDADDR: No such device
eth0: ERROR while getting interface flags: No such device
eth0: ERROR while getting interface flags: No such device
Failed to bring up eth0.

After a lot of web research, in which I found mostly old postings from
around 2006 when these cards were apparently new and not supported, it
appears that there are a lot of cheap fakes out there that are really
Silan cards and the correct driver is sc92031.  Loading this driver
also causes no errors, but when doing ifup eth0 the same errors above
occur.

So, does anyone know what card I really have?  Everything I've read says
that it should work with the sc92031 driver, but it doesn't.  Do I need
a different driver?  Which one?  Or is it hopeless and this ethernet
card is only good for the garbage?  Any hints will be greatly appreciated.
Thanks.

A.