Haha!!! got it!!

Erratic operation lead me to think it was a software problem, but good think you takled about VCC!!

I actually put my ajustable regulated powersupply and checked again... VCC was 7.5V!!! but everything else was working fine!

I will have to check what's going on with my 7805, but in any case, when VCC = 5V, the EEPROM works, and i can retrieve the correct values :-)

Well, as always it is super simple when you find it out! (took me 3 days though!!!).