The vems unit was bought as a plug and play, with the supplied wideband - from DP engineering.
The support pages clearly states no to touch nernst and and pump zero PW.
The supplied wideband is just a regular LSU4.2 wideband sensor. The values you mention are the ECU calibration values, not the sensor calibration. I'm pretty sure something's still not right even though the separate AEM gauge seems to agree.
I can try to upgrade to 1.2 but if things get messy, i wont have any kind of support and i will stay stuck with a unit which doesnt work and a dead car (its my daily car as well). So i am not too enthusiastic to do this.
It should be pretty simple. After the firmware update wizard is done with it's work it should have uploaded a new config for the firmware version you just upgraded to. Use the "validate config" button to sort out any new and old settings that are not set right, some are this way to get your attention and not to bother you un-intentionally.
If you create a report from within VemsTune (see Help menu) and post the link here, someone (maybe me), can take a closer look at your new config file if you can't get things going like they used to. If you only describe the problem and don't present any config file to us then help will be that much harder to give.