Motherboard voltage / temperature CRAZY

Greetings,
    The computer i'm having trouble with has the follow parts inside: an Asus P3V133 MB, slot 1, with celeron 450mhz, 192 mb ram, (one 128, and a 64 obviously). Power supply is a 300w. In the AGP i've got Voodoo Banshee. PCI's are a Actiontec modem, and Sound Blaster 16 in the other. 2 CD drives (CDR and CD) 1 HD (maxtor 80gb 7200) and of course a floppy. Also there are two USB devices, a flatbed scanner and a printer. (hope that's enough info)

    Prior to the SB16 in the PCI, I had a SB16 in the ISA which sounded aweful, so I switched it with the PCI. Now when I turn the PC on, it sends me to the bios saying the voltages are running amuck. Never had this problem before. Here's the numbers i've been getting:

       MB temp (RED) goes from 0 degrees to 255. (i'm guessing the minimum and the maximum allowable ranges)
       Vcore (was 1.98 to 2.0) Now is 4.1
       +3.3 is now +4.1
       +5 is now +6.9
       +12 is now +15.5
       -12 is now -14.2
       -5 is now -6.1

     Now what's really odd to me is that SOMETIMES after turning the power on, I can go straight in the BIOS and all the above values and temp are perfectly nominal... however give it anywhere from 8 seconds to a minute, and they all turn red with the numbers above. I'm afriad to keep it on for fear of shorting burning something out.

     So my question is this: Does this sound like
a) a power supply problem (the power supply is only a year old - it's been replaced)    

b) a motherboard problem, either the sensors have gone insane, the mb is shorting out to the chassis, or maybe a bios update would help?

c) somehow removing an ISA and replacing it with a PCI screwed something up.

or d) none of the above.

  Thanks in advance for any help.