There was/is an issue with certain Maxtor SATA hard disk drives. In some cases, it is necessary to force them to SATA-I mode (1.5 gb/s). There's a jumper in the back for that.
Yep, set that :-)
4 x Maxtor 250GB SATA drives(Incidentally I would recommend against making a RAID array from several drives from the same manufacturer. Especially if they're the same model. Even more so if they're the same batch.)