Didn't the mighty US of A come a cropper trying to sort out a similar problem in Somolia? Being 'peacekeepers' in the middle of a civil war alongside ineffective UN troops?
There has to be a concerted effort from all the UN parties - I would suggest that european troops would be seen as invaders and would probably make the situation worse and maybe unite the warring factions.
I don't think we can get involved in a purely 'humanitarian' role in this part of the world - life is cheap and I for one don't want any pictures of 'Black Hawk Down' style incidents with British troops.
The UN is a toothless tiger - it's up to the AU to sort out their own backyard. We neither have the will or the resources to contemplate becoming involved in the Congo.