sensors, how good are the readings?

Having installed sensors on my SuSe 7.2 desktop with gkrellm as monitoring device I wonder how good the readings are that sensors shows. On sensors there is a reading for VCore1 and Vcore2. The reading for vcore1 lies in between the min max, but the reading for the vcore2 is with 1.5 volts lower as the 1.80 given as minimum. As I have no idea, first what this means :-) and second how good and trustworty this reading is, I would like to lknow if I should be getting nervous ;-). Another info which I do not like that much is that my minus 5 Volt (min -4.5 and max -5.48) lies with -5.72 out of specs. Alarming or ...? Your input/thoughts to above are highly appreciated.