1.4\'s overheat something chronic. I work in a PC store, and we have lots of trouble witht them. Try the following:
1. Make sure your video card has plenty of room
2. Put your SB Live in any odd numbered PCI slot (but not number 1, its too close the the video card). I know this sounds wierd but hey, trust me.
3. Take the side panels off. This allows better air flow
4. Get a deacent fan. By deacent, I mean you\'re spending at least AU$50
5. Get a copy of ZD\'s Winbench, and also the PC Probe thats on your ASUS motherboard CD. Then set it to alarm at 58 degrees celsius, and run Winbench. See how long it takes to overheat.
If its not a heat problem, I dunno. But its my experience that Athlon 1.4s are bastards when it comes to heat