Well, unfortunately I believe being lucid and having control are two separate things. Control (from what I understand) needs to be learned.

I also have that problem in some cases. I think it really comes down to how confident you are in the dream about what you are doing. You have to really believe that what you want to happen will happen. I know, sounds kinda Peter-Panish, but.....

I am usually able to fly at will - because this is one of the first things I was able to do when LDing, it is something that I am confident will work. It's something I expect to work. One fairly simple thing I've been trying with no success yet is to summon other characters. You'd think that would be as simple as just yelling out "dream characters, appear now!" But so far, I end up just sittin there like an idiot very lonely.

So, I guess all I can suggest is try to think of things you want to do before you go into dreamland and try to convince yourself in waking life that it will happen in your dreams - because in dreams, it's all possible, ya just gotta believe...