Pretty much that...
DD2 was 2 at the beginning of this month. She has never really slept through. We had a 6 week stretch around September last year when she slept through 3/4 nights a week. Then she got a cold and it ended.
She wakes any time between 2am and 3:30ish and comes into our bed then as it's the only way to be sure we all get some sleep. This has been the routine since we stopped co-sleeping all night around her first birthday. She goes to bed ok - I sing her a song, give her a kiss and leave while she is awake. So she can put herself to sleep.
But she just doesn't sleep through and as she gets bigger it's becomming more disruptive to have her in bed. And I am very very tired! 
We have tried patting and rocking. We have tried just sitting in her room with a hand on her back. We have got into bed with her to settle her. We have had three goes at leaving her for a while to cry (i.e. doing it over a few nights, not that we've left her just three times in her life). That makes her very very upset - beyond what I think is reasonable so I don't think it's fair to her. I've read NCSS, Healthy Sleep Habits Happy Child, endless websites but all either deal with babies or talk about evening routines, which we have.
Does anyone have any suggestions for me? A full night's sleep would make an incredible difference to our lives....