Large HD support issues - clunk of death?

[Peter Loron]

I've got a K7S5A Pro mobo. It has been running FC1 for quite a while 
with no issues. I wanted to run FC3 and have more space so I swapped 
out the 10GB disk and put in a Seagate ST3300831A 300GB unit. It was 
properly recognized during FC3 install. After completion of 
installation, I ran some updates via RHN and apt-get. No problems. 
After sitting idle for a few minutes, I did an 'ls' in the terminal. 
The drive made a "clunk" sound, the disk activity light came on, and 
the machine was locked up hard.

This basic scenario has repeated itself several times. Once while 
installing FC3 again, the clunk happened when I clicked Next after 
setting the NTP server.

Any ideas? Does this mobo and FC3 simply not play nice with this disk?

Thanks.

-Pete