system/cpu temp difference

At idle (surfing use only) my system temp is 30c while my cpu temp is 45c, as reported by Speedfan. Is it normal to have that much difference in temps? or does it mean I have a poorly performing heatsink? It is the stock AMD (I think) which I have lapped and is using an unknown brand of thermal paste at the moment.
I have 1 intake 80mm fan and 2 exhaust, plus PSU fan.

15C isnt that big of a diffrence.
However the stock HSF on the older XP cpus where not that great. and the Palomino cores ran hot as it is.
so I wouldnt worry about it, if you really want your temp lower,
look at a Volcano 9, 11 or a slk 800 or 900 w/ a tt smart fan.
-L_P

For the moment (I just got this computer) I am trying to get it all the basic stuff sorted out so I can think about OCing it a bit. I know the MB I have sucks for OC but it will be the first thing to go. (what do ya want, the whole thing, including a 17" monitor, was only $200)