Did you try setting PCI-E freq to 100mhz?
- Yes, it has been always on that value.
Also try upping the northbridge voltage a tad.
- Why? My board has been always working fine with everything on [Default] with my 7100 GS.
A BIOS update may help aswell
- The only BIOS update for the G41M-ESL2 F4 rev. 1.0 is F6 (F5 is only for rev. 1.1) and F6 update address an issue with the Wake On LAN and has nothing to do with these type of problems.