This is pretty much how I feel about the influence system in KotOR 2. It's extremely finicky so far. In one conversation involving about 4 lines of dialouge, I managed to gain and lose influence with the same freaking person. You'll also have one random comment affect influence, while a similiar comment later has no effect. It's just a little wonky.
Only other thing I'll mention is that I'm level fucking 11 and don't have my lightsaber yet. That's got me grumpy. Other then these few little problems, the game's pretty damn good, and has me hooked.