Ok, first question: Are you trying to install GPE?
Next question: have you setup your repositories as in: http://maemo.org/community/wiki/appl...nrepositories/
3rd question: If you are trying to install GPE, after checking your repositories, browse (on your tablet) to http://gpe.linuxtogo.org/~florian/maemo/ and use the installers there.

At least, thats how I got GPE installed on my tablet yesterday.

Hope that helps!