Apparently the temperature sensors on an awful lot of AMD aren't actually on the cores or something? So the reading given is actually a lot cooler than what the cores are. I've got the same problem. with my 1055T. Idle temps for me are about the same (18-19 degrees celsius) in a room that's about 21*-22*. No idea why some readings are more accurate (Like the BIOS.). The best way to figure out how much its off by is to leave your computer in sleep mode, with your temperature program running. Leave it for a while and when you turn it back on, the low temperature should be that of room temperature. I've found mine is about 13* when I turn it on, meaning its about 8*c below what it should be. Yours may be the same or not, but give it a try. Just make sure you leave the computer long enough for it to cool properly.