Weird shut down problem

[mritz]

I recently installed XP with 98 on a dual boot
everything working great..but now when I do a system shut down it will power down and then
the system will start to pulse on and off until I hold the power switch in ??
It does not matter if I am using 98SE or XP I get the same thing when I shut down

XP & 98SE dual boot Maxtor 30g ATA100 7200
Iwill KK266 W/1.33 Tbird
40g ATA100 7200 Maxtor
the 30 & 40 Are connected to a Maxtor ATA100 Card as drive IDE 1 And 2
IDE 1 on m/b DVD rom & 56x Acer CD Rom
IDE 2 on m/b H-P CDRW
USB SMC 10/100 NIC
Radeon AGP AIW 32m
Live Sound card

Installed all the XP drivers I could find for the diffrent Hardware
any suggestions ??
Is it poss that the ATX power supply is the cause (enlight 300w AMD aproved 1.4g)

[JJ]

up 4 a buddy

[Jim Z]

try removing different cards and see if it quits. Could be a device spitting out spurious crap that's screwing with the power management.

[mritz]

JimZ Thanks
actualy forgot I did add 2 pieces of new hardware while installing XP
turns out it is the SMC USB NIC causing the problem disconect it and problem is gone
toooo weird

[chottoED]

should've gone dlink