I'm installing Kubuntu Gutsy Gibbon onto my Dell Vostro 1500 and the first problem I hit was that the Live CD was entirely unable to repartition the disks. There are a few partitions on the disk (as you'd expect from a Dell machine running Vista, its got recovery and things) and I kept seeing the error:

An error occurred while writing the changes to the storage devices. The resize operation is aborted

To get around this I resized the main partition in Windows and created a new partition but left it unformatted. When I went back to the Live CD install I got the option "Use largest contiguous space" and that worked fine.

Hope this helps someone!