Don't worry, that's normal. If you unlock the cores then for some reason that I don't quite know enough to explain adequately the temp sensor won't work. To the best of my knowledge the way to go here is to get HWmonitor and use the motherboard temp sensors that are near the CPU. The only way to really know however what is normal or not is to have used HWmonitor before unlocking the cores to get an idea of the normal temps.
My advice: Get HWmonitor, go back to x2, check the temps under load with say Prime95 or something similar, ignore your core temps and look at the motherboard temps usually tmpin 0, 1 and 2 if memory serves. Work out which one climbs with load on the cpu as this will be the sensor for overall cpu temp (rather than cores). Then unlock the cores and check with the same sensor with HWmonitor while loading the cores to make sure they are rock solid stable.
You probably know already that the max temp for that chip is about 70 degrees celcius, I personally wouldn't push for more than 60. Are you using an aftermarket cooler? Even a cheap Coolermaster Tx3 or similar will be WAY better than stock. If you intend to overclock as well just keep in mind that an unlocked chip won't overclock as far most of the time and may need voltage bumped up some to remain stable. Max voltage for this chip is 1.4v, some go higher but I prefer not to.
Lucky for you that yours unlocked. Mine didn't, but that is most likely due to my dinky motherboard that won't support 125w cpus properly. I'll try mine again when I get a new MB.
I welcome all newcomers to Tom's, but this kind of post I don't think is very helpful or welcoming. Please don't post this kind of thing if it isn't helpful to the thread.
As for the original poster, when unlocking cores on any of the AMD chips, your temperature software and also CPU-Z will not report the correct things. Sometimes the temp sensors will even say -127 C... which is nonsense. If you did get all four cores to unlock and they are stable, do not to overclock the chip until you can verify the actual CPU temp. If one of the programs listed above works out for you, make sure it is under 65 C when under full load or stress testing... if it is near 65 or over... you should get a good aftermarket cooler or turn the unlocked cores back off for thermal safety.