Hmmm. Where is developer-support? It isn't included or installed with the release tarball. And it isn't available (doesn't appear in the list of installable packages) in the repository.
Both acs-mail-lite-0.1d.apm and acs-developer-support-5.0d3.apm are in the repository. It looks like the automatic installer refuses to see them - this could be a bug in the installer or there could be something wrong with the package. This leads to a number of other packages being uninstallable. A workaround is to download them directly and install from local, and then go back to using the repository.