I fixed the problem by downloading the linux driver for my NIC(RTL8101E) from Realtek and compiling it:
There are very nice instructions on how to do that in the archive.
For instructions about how to load the driver at start up in OpenSuse go to:
It seemed that the problems was that:
but it didn't worked for me. Perhaps the above solution is applicable to Windows XP or to an older driver of realtek for windows. In my case the MAC address was just zeroes and I didn't find anything similar online. Also ethtools eth0
gave wake-on: d
no matter what was set as an option for shutdown wake on lan in vista.
Thanks for your replies.