Using motherboard monitor? My PC's the same way - 1.52v for the "3.3v" setting. I get the idea that MBM5 might just be reading the wrong thing. The AGP slot uses 1.5v, that might be what it's actually reporting; if the system's using DDR, I think that's 2.5v. I don't know what does still use 3.3v - maybe the PCI bus?
I wouldn't worry about it though - if the system's running fine, it's getting the right voltage where it needs it. If it was only getting 1.5v where it needed 3.3v, I doubt it would even boot.
