Hi PegLeg44.
Generally, older versions of Linux do not support the latest versions of apps, including GIMP. It's might be possible to install GIMP 2.8.x on Ubuntu 10.4 but you will need to rebuild many GIMP 2.8.x dependencies and underlying libs that are outdated in older versions of a given Linux distro, including Ubuntu.
Quote:
Currently there is no method to install Gimp 2.8 on any version below 12.04.In terms of is it possible ...
Unlikely for the following reason:
The dependencies of the latest versions of Gimp require a-lot of the latest underlying libraries that you will not find by default in any version below 12.04. Thus, you will need to recompile and rewrite portions of the code to get it to compile. The further away you get from 12.04, the larger the change required.
A maintainer of the Gimp package (ppa:matthaeus123/mrw-gimp-svn) mentions in the description that it needs the latest Gnome-3 PPA as well as some other testing libraries. Both of these will not install on gnome-2 environments (below 11.10). Looking at the dependency lists for 12.04 version of Gimp, these are also not available in 11.10.
Since you have just installed Ubuntu 10.x, it will be much easier for you to to just dump that and install the latest version of Ubuntu. Trying to rebuild those old dependencies will be opening up a huge can of worms and it's just not worth it.
You really don't want to start out using such an old version of Linux, anyway. Even if your PC is kinda dated, you can always go with a lightweight Desktop Environment, like LXDE or better still, MATE (fork of Gnome2).