If you're using Ubuntu (or Linux Mint, or Mepis...), you're really using Debian with some enhancements.
Oh, please. I hurt when I hear people saying Mepis, Knoppix, Xandros or whatever is Debian [except foo]. A non-insignicant portion of questions on Debian forums is about derivatives, please don't encourage. If your Debian-based distribution has some issue, Debian people most likely can't even help you. If the distribution you use is not Debian, then you're really *not* using Debian. Most people forking take Debian, remove half of it, add themes, a few "user-friendly" interfaces, a couple of bugs along the way, then proceed to shipping something twice more outdated that they won't maintain. If your problem is with an outdated piece of software, Debian people cannot help you. There are, however, some "distributions" that *are* Debian. These are called Debian Pure Blends, see http://en.wikipedia.org/wiki/Debian_Pure_Blend
Doubt is a pain too lonely to know that faith is his twin brother. - Kahlil Gibran