...but the symptoms were different to mine. For me the r8169 kernel driver always worked stable and without any problems when booting directly into Linux. With the AsRock Z68 Pro3 it now only worked reliable as long as Windows was not in between reboots, but besides that I have also nothing to complain. The ASUS P8P67 had no problems at all and that is why I still believe that there is something at least suboptimal within the AsRock UEFI.
on kernels after .38 you get no connectivity at all. .38 sort of worked but disconnected constantly.