The HP T5540 has no Fans, that's correct. I am not sure about the 0,053 VCore: it seems me too low, even for a VIA C7-M ultra low voltage processor (non-ulv VIA C7 models need about 0,8 Volt) The voltage does btw. not change under heavy CPU load.
The HP T5540 is a thin client, maybe the voltages are different from usual desktop systems? (It has an external PSU which provides 12V/4,16A to the thin client)
Too bad that the thin client has no temparatur sensors
I think your motherboard simply doesn't utilize the sensor features of the VT1211 chip, so all readings should be ignored In case you can ask HP directly about that, please let us know if there's a trick we should use in AIDA64 to make the readings work.