Is it normal for one core to be much hotter than another?

[Juked07]

Just got my system up and running last night and ran speedfan at stock settings. I don't have much experience, so I'm not sure if my temps were good, and I thought it was weird that one of my cores in my C2D was a lot hotter than the other one. They were something like this idling (sorry if I get this wrong I'll correct it when I get home):

Core 0: 35
Core 1: 48
Core: 50 (What is this the temperature of? Is this the motherboard?)
Ambient: 41

I'm using the stock fan that came with my E8400, but isn't 48 a little high for an idle temp?

 

[Homer Simpson]

i dont recall the exact temps, but my 8400 had a 10-12 degree discrepancy between the cores at idle and load. that was with the stock hsf and an aftermarket one, both with AS5. since its pretty common for the sensors to be off +-5, i just figured i had one +5 and one -5. it would explain the difference.