Yep, Dell actually fixed that with the XP SP2 discs. The problem with this particular model as well as the rest of dell machines sold between sept 04 till december 06 had what was called MRI, Media Reduction Initiative... which meant that there was a restore partition on the primary boot drive. With this, they had eleviated the need of loading those drivers. What was left if the drive was ruined was a call to dell tech support for install media, shipping time and then a few hours reinstalling and updating the OS.
When Vista shipped, things went straight to hell at first then cleaned up nicely.
So, what was dropped in your lap was a system that was setup with a factory installed work around for the lack of integrated sata drivers in XP.
HP on the other hand, did it right. They built into their system bios, the ability to "Disable SATA Native Mode" which in turn runs the SATA controller interface in a sudo IDE mode which can be re-enabled after the OS is installed.