your Mobo is wake ON LAN capable, enter BIOS, ou'll find his option of Wake on LAN, disable it. your PC wont wake up then. (u might have to use water bucket)
Intel Core2Quad 2.66Ghz 12MB L2-Cache
4096MB DDR Kingston Hyper-X
XFX 9600GT AlphaDog
Seagate 2 X 320GB SATA2
LG L246WH Flatron 24"