Hi Myrek
I am not sure if any of your system settings have changed somewhere, but if you are able to receive an acknowledgement from the eeprom (connect) and the GetConfig would be reading it... so I can see how this confuses you !
From some testing experience - I would look toward the green wire coming out from the usb plug, this is wired to the cruise input on the controller that functions as a clock/enable signal.
If you can perhaps try it on another PC running win2003/XP would be a good start, then maybe look at the wires coming out from the USB...
I really hope somebody has not written to your eeprom sneakily 1 million+ times!
IC's are tricky though, there is the super slim chance the last time you programmed it there was some kind of error, spike, who knows that could have ruined its ability to write but it would be very unlikely.
I've had many of avr & pic chips fail to an extent that only some of the input/outputs work, but can still read and write to the chip. Then some very few that I could read, but no longer write...
