The Particle Data Group has responded to the letter I sent them regarding the strange behavior of the Strange D, which seemed to not conserve charge in its decays. Their response is that the decay in question is really the sum of two different decays. The two actual decays are listed below the summed decay. I checked and using those two decays does indeed work correctly. As far as I know, the Strange D is the only particle that uses this "summed" notation.
Anyway, while I was waiting to hear back from them I found another unusual decay that doesn't seem to conserve charge: the Charmed Lambda. Decay #10 of this particle gives a decay whose total charge is neutral, whereas the Charmed Lambda has a negative charge. And there's no "summed" notation for this particle as far as I can see. So I've written off another letter hoping they're nice enough to respond once more.
That said, the extended Particle class is nearly done. Once these remaining few issues are cleared up, it'll be published.
Charmed Lambda Info: http://pdg.lbl.gov/2009/listings/rpp2009-list-lambdac-plus.pdf