Per a report from Chris Tapp on the Yocto mailing list: "I renamed the root for my new layer from 'meta-ebox-3300' to 'meta- ebox3300', updated this in bblayers.conf and now my defconf file is found as I was expecting... It seems as if having -<numeric> at the end stops things working." https://lists.yoctoproject.org/pipermail/yocto/2011-August/004562.html
Since nobody can reproduce this at the moment, closing until someone can demonstrate the problem.
Verify, WORKSFORHIM :-)