K7T Turbo, KT3 Ultra and XP1800+

Ok, here's the problem. I bought an Athlon XP1800+ for my K7T Turbo m/b. I also purchased a new, 300 watt AMD approved power supply and upgraded the bios in the m/b. The system will not boot with the cpu!! I've had the cpu and power supply checked, and the m/b works fine with my Duron. Any ideas as to what's going on? I'm having the exact same problem with my KT3 Ultra board, too!

System specs:
Win98se/XP
MSI KT3 Ultra m/b
256 mb DDR PC2700 name brand ram
1 20 gig Matxor hd ATA 100
1 10gig Maxtor hd ATA 66
GF2 GTS
6 channel sound card
Lan Card
CD Rom
CD/RW
300w p/s
-----------------------------------------------------------------------------------
Win98SE
MSI K7T Turbo
320 mb PC133 ram
1 40 gig Maxtor ATA133 hd
GF4 MX 440
CD/RW
4 channel sound card
Lan card
300 w p/s

I have left a posting under AMD CPU. You might get told off by the moderators because they do not like duplicate posts - wastes space etc on the server apart form getting confusing.

Sorry-I really wasn't sure which category this fit under. Mods, go ahead and just delete this thread.