Big difference in core temp

[corex2]

I got a 10c difference between my cores on my e8400 when at idle but underload there the same,
is this a sign of a problem?
My cooler is a 9700nt from zalman and is well seated with thermal paste applied correctly.
I'm a little worried ! Here is some screen grabs -

 

[corex2]

I just had a chat with live tech support at Intel and they recognize this problem and will accept a RMA.