Unfortunately, some of them are giving S.M.A.R.T. errors. I put one in the newly reconditioned HP Proliant ML350 G4 that I'm setting up as a Debian "squeeze" box. The kernel log is full of messages that say: "Logical unit failure prediction threshold exceeded".
Looking into the matter, I found that the Linux kernel is printing these messages because the S.M.A.R.T. circuitry in the drive is tripping. The messages were occurring every time I accessed the drive (read or write).
I found no solution to the problem, but I did get rid of the messages by turning off S.M.A.R.T. as follows:
# apt-get install smartmontools
# smartctl -s off /dev/sdb
# smartctl -i /dev/sdb