CPU at 37C means its very cool...
My C2D OC at 2.8 GHz runs idle at 48c and on load at 63c !!!
See with Core 2 Duo, unless u cross the Limit of 55c idle and 70c on load, u are fine, though i try to stay bellow 65c on load....
About the MOBO, run a test, open up the work side cabinet lid, and the see if the temp is coming down or not,
some time bad assembling can cause wires in side to get tangle and mess up to trap the hit in side them

, so try to short out that problem if u see thats the case