If you conquer/influence flip a world you don't have the technology yo colonize, it stops producing any production/research/whatever points. That could be your problem.
MaleWhiteCorporateOppression
It's certainly more intrusive than SDC, but it's not as bad as people say. The main thing is that you have to have STEAM running if you want to play STEAM games. You can play in an "Offline Mode" but it's pretty uncooperative and you need to still run STEAM anyway. It does have a built in IM/Friends system that lets you chat with friends ingame or out of game and join whatever server your friend is playing on automatically. It's really not that bad and is often very convenient
SupComm is certain one of my favorite RTSs. It's big, fun and explody but still requires a lot of strategy and concentration. I have a 3.2 Ghz single core and I can play 1v1 and campaign with little to no problems and 2v2 with slowdown only during the largest battles. Anything bigger just asplodes though.