Narrative point of view and voice

I'm nearing the 20,000 word mark of my redraft but I'm beset by this feeling that 'something's not quite right' about it. Having shown it to friends, I'm starting to be convinced that it's something to do with the choice of narrative point of view and getting the voice right.

The first draft of the novel was written in the first-person, in the voices of the two protagonists - Lorna and Tag. I decided to start the re-draft in the third person because I was finding the first person point of view limiting, particularly in the case of Tag. It's a key feature of Tag's character that he is essentially illiterate and so maintaining the consistency of his voice in the first person was difficult. I really wanted to make sure that I'm conveying the real horror of his life as a homeless young person and I didn't want to be restricted to his vocabulary to do it. Besides which, I feel too far removed from his background to be sure that I can inhabit his voice and be authentic enough.

I'm now trying to write in the third person which feels better to me but sometimes I feel like I'm falling into the trap of slipping between narrative voices when I don't mean to. I'm also still plagued by the idea that the book might work better in the present tense after all but I'm concerned that it might be harder to find a publisher for something in the present tense, particularly when it's targeted at young people.

Anyway, I'm off tomorrow for a NAWE retreat in Wales and I'm hoping that some sea air will do the trick and that suddenly it will all fall into place. That's assuming I don't fall apart from the stress of being separated from my little girl for five days.