On your specific problem: Pull the drive and run manufacturer's low level diagnostics on the drive, including the low level media analysis; the destructive one that takes a couple of days if you have nothing irreplacable on the drive. If the diagnostic returns an error code, get the drive replaced. I don't necessarily recommend you keep the drive warm and cozy while running the diagnostic. <g>
In general, everyone has their favorite brand of drive. I think someone has reported oddball problems with every drive brand out there - problems that were resolved by replacing the drive. About a year ago the general consensus was to avoid the IBM Deskstar line of drives (now available from Hitachi).
Reports are also mixed on the newer Seagates; they have a 5 year warranty, but may lack acoustic management capability.
PlainBill
There's a difference between needing help, and just being plain ole' lazy.
"You cannot teach a man anything. You can only help him find it for himself." Galileo Galilei (1564-1642)
HR20-700 with 2 TB, HR22-100, HR22-100, HR22-100, HR23-100 all running 0x5cd and networked.