Well, you want to install it to the second partition, is that a partition you have prepared?
I have found that 7.04 doesn't really do the trick for me, Gparted pretty much recognizes all my partitions take a few hours and i reboot to find nothing at all on my HDD, i kept track so i can restore them by simply using testdisk.
I prefer pretty much anything to Ubuntu, I'w go with Zenwalk but Yoper or Arch is nice too, if you really NEED Debian (if for nothing else then for it's amazing support when it comes to the repos, only other distros that have anything even comparable would be Yoper or Arch) then just use Debian, it's way better than ANY of the distros based on it.