I did the following:
I downloaded the full 2.6.9-rc2 tree, from which I retrieved the single file via-rhine.c that I put into the Debian 2.6.8 tree. I compiled the modules with the same config as my current kernel, I retrieved the new via-rhine.ko and loaded it in the current kernel.
The only difference I see is the kernel error message : eth0: transmit timed out eth0: Transmit timed out, status 0000, PHY status 782d, resetting... eth0: link up, 100Mbps, half-duplex, lpa 0x40a1
