Ah I've been using an adapter to convert an IDE HDD to SATA,
I have both SATA only & IDE converted HDD and neither work 100% via SATA connection,
I borrowed a friends PC the other day and linked my main HDD into his mobo
with my SATA lead and it didn't crash so I guess it is my mobo
If I use my IDE HDD via IDE then it doesn't crash so it can't be RAM or the CPU,
it must be the SATA connection, I've also tried all 4 SATA sockets and have the same result.
So I guess I'll be buying a new mobo sometime soon...