3.0 beta3 -- repo problem?

greetings! there seem to be a number of conflicting recommendations about what repos to enable... for a 3.0 beta3 system, what should we be using? if i try to enable "main" in stable and testing, i get this error: Failed to fetch http://apt.64studio.com/64studio/stable/dists/64studio/main/binary-i386/Packages.gz 403 Forbidden Failed to fetch http://apt.64studio.com/64studio/testing/dists/64studio/main/binary-i386/Packages.gz 403 Forbidden Some index files failed to download, they have been ignored, or old ones used instead. thanks... cheers! .pltk.