Unreliability or a bad unit?

For years I praised the reliability of Sun systems. I did have some good experience too when systems ran for months before being rebooted. That was one reason why I bought so many Sun systems over the years - sparcstations, ultra-5s and then sunfire v100. I was so excited with my v100 that I told pretty much everyone about it who ever discussed Sun systems with me. One day it bailed on me for no reason. First I thought it was the bad harddisk. I tried booting the system with a CD after removing the harddisk from the system but to no avail. I tried quite a few things from the PROM prompt as far as I could know. My belief of the reliability of the Sun system shattered. It shocked me as it was my database server and so was the CVS and also had my web servers running. I forgot what data I lost but they were plenty. I bought a new harddisk to replace the old one and would try to get a brand new build. I have not tried it yet but I don't think it should work. When at Sun we challanged the reliability of PCs, this incidence has raised some serious questions.