Checksum Error on TH7II

Hi,

one week ago I purchased an Abit TH7-II. In the meantime I did some overclocking and Upgrades to Mr. N´s 7D Bios and everything was running quite fine.

Since two days ago I get an error messaging saying "CMOS checksum error" after cold booting my machine. All Bios settings are reset to default afterwards. If I simply turn off the PC without disconnecting the power plug this problem won´t appear. As soon as I unplug the power cord and put it back in, I receive this error msg.
I flashed CMOS with official Abit´s 7C Bios but this was no cure

I checked the CMOS battery then but it´s still loaded with 3,03 Volts. Up to the label this voltage should be correct.

Do you have any suggestions for me?

Thanks and best regards
Perc

One thing I forgot:

I get this message just with BIOS 7D - with BIOS 7C there is no message at all but all my settings have gone with the wind.



// EDIT

After some tests with different batteries it seems like the CMOS jumper had no proper contact. It just looked like being properly attached

Sorry for bothering you guys