System temp vs ambient

MBM is showing my 'system' temp as 33-34C [with light useage]. Room/ambient
is 19-20C. Does 13C rise from ambient seem right? MBM indicates a 9-10C
rise from system to CPU. Does that seem right? Outside of the case feels
like same as room temp - i.e, slighly cool.

Case is Antec SLK3700BQE, just 1 rear fan [exhaust]. Also, adding the front
fan [intake] doesn't make any difference in temps - although it seems to
'recover' from temp spikes a little faster.

MSI K7NV, 2600 T'Bred, MSI ti4200, two 7200rpm harddrives, 768mb 333 DDR.
No overclock setting on anything.

thanks