Just remembered another thing. Even when I'm not using Phoenix miner I seem to get quite high rejected shares rate when checking from the mining proxy database. When I check mining pool dashboard though it is all fine. So I guess this proxy currently marks certain bad connection issues or something similar also as rejected shares while they are really not?

But yeah PulsedMedia.. I wouldn't be surprised if your issues are partly caused by phoenix. I'm going to testrun poclbm in Windows on my machines today.. this far it seems very stable with this proxy as rpcminer clients.