if the mobo that faith4 posted is the same as ur mobo, then it does have dual core support. In that case if u want a new cpu I'd go with an amd x2, they are pretty cheap nowadays. Maybe a 3800+ or a 4400+.
Going for core 2 duo would probably become a little more expensive, since u would also need a new mobo, and probably new ram too. Though there might be core 2 duo mobos with ddr support, but atleast most of them use ddr2.
