I second the master/slave issue. Some drives have very specific jumper settings like MASTER or MASTER WITH SLAVE PRESENT. Autodetect doesn't always work.
Do the drives spin up?
Have you checked your cable?
Would it work if you used one at a time?
Sometimes bios issues can make you think that you can use both IDE and SATA ports at the same time, but it takes a setting change. For instance on the ABIT IC7 and IS7 series the board had to be set to "enhanced mode" to accomodate both sata and IDE at the same time.