Inspiron 530 and Enterprise 5 derivatives
The Inspiron 530 run RHEL5 and derivatives fine, with one problem:
The normal load order of the ata_piix and USB drivers causes a race condition; this is also tru for normal Ubuntu, but Dell has fixed this by changing the way they load the modules.
For RHEl5 (and probably also Fedora)
1- In the BIOS under "Integrated Peripherals" set "SATA Mode" to "RAID".
2- Install Linux; you will not be able to boot into VISTA
3- After install, in linux as root make a new ramdisk with the ata_piix loaded before USB (mkinitrd --preload=ata_piix --image-version /boot/initrd <kernel version>)
4- Reset the bios to use IDE rather than raid.
You can skip steps 3 and 4 if you only wnat to run Linux.