Converting files is very processor heavy, that temp is just fine. You need to worry if it gets over 60C. Newer P4s run hot. THat is an average temp. Just raise your warning alarm to 60C. Most new P4s wont even begin to fail until they hit 69C-70Cish. Hope this helps.
EDIT-Oh ya, and your mobo software should be fine. If you are worried, double check it with BiOS readings. And if you want a good freeware program, get Motherboad Monitor 5 or MBM5.
C2D E6420 2.13, FSB 1066MHz
OCZ SLI-ready 1066MHz 5-5-5-15T
eVGA NF63 motherboard
eVGA 8800GTS 640MB
Sound Blaster Audigy 2 ZS
Windows XP Pro 32 bit
OCZ GameXstream 700w PSU