Hello all, been a while, technical difficulties

Anyway I need your advice, since I upgraded my PC I noticed my CPU temp is good but MB temp fluctuates, since ive never had a system that could measure temps before, im not aware of normal MB temps, please consider the following:

Celeron D 2.8GHz CPU
512MB DDR 400 Ram
Asus board

CPU, 34 Cel (right now)
MB: 35 Cel (right now)

Ok so what I notice is, on a boot, my MB starts out like 36, and slowly increases to 41, then fluctuates. I installed a fan in the back as exhaust, and my PSU has two fans, its a thermaltake.

Is 35 - 41 normal for a motherboard, I was actualy reaching 45, getting alarms, untill I put in the extra fan, but now it does not hit 45, just idles around 41.

Whats normal? And is there a good refernce, I find resources on CPU temps but none on mother board temps.