okay - I did indeed say 'rich black' for those shadows, but now (groan!) I think they don't have a relationship with the colour palette of your scene :-(Are your shadows on a layer? I'm going to suggest you start over, Molly - I know this is NOT what you want to hear, but this scene is working well - the shadows are not; I think you need to do more picture research into shadows - look at their opacity/transparency/diffusion - for instance, the shadow edge nearest the light source would be more diffuse - and everything would feel more feathered at the edges because of the diffuse light source. Don't despair, Molly! Motor through it!
... still thinking about your image, Molly - are those shadows in perspective? I think part of the issue is they don't seem connected perspectivally (is that a word?) to the rest of the image - I don't know why, but think this image will be useful...http://www.bitey.com/images/blogImg/shadowRoot/campfireShadows.png