Whaat, I just reproduced it very easily. Are you using a fully-installed 12.04.4 system? that may be a difference, I've seen this on systems that are in the process of being installed (e.g. a live CD environment), though I think there should be no difference. I'll try installing first and then trying to replicate this.
Anyway, I'm attaching a diagnostic log produced by apt-get --dry-run -o Debug::pkgProblemResolver=1 install plainbox-provider-certification-client.
Whaat, I just reproduced it very easily. Are you using a fully-installed 12.04.4 system? that may be a difference, I've seen this on systems that are in the process of being installed (e.g. a live CD environment), though I think there should be no difference. I'll try installing first and then trying to replicate this.
Anyway, I'm attaching a diagnostic log produced by apt-get --dry-run -o Debug:: pkgProblemResol ver=1 install plainbox- provider- certification- client.