tinned or dried? If dried, you might not have soaked them long enough, if tinned, they salt them and salt toughens the skins during cooking.....use dried and soak them over night yourself!!
Mercia i tried to make some the other day and it came out nothing like the beautiful tesco's branded hummus with corriander and lemon, I used tinned. So you're saying that the dry have no skins?
As the end product will be blitzed in a food processor I don't really think it is necessary to remove the soft skins. The key I think is getting the right balance between tahini, lemon juice and garlic. I've made it many times but I've never noted my measurements, opting instead to judge by eye - as a result the really good ones I have made have been down to chance and impossible to repeat.
I soak the tinned ones for ten minutes before using them. It is partly to do with the right balance of ingredients, partly to do with how finely you blend it and, the magic bit, add a tiny bit of water and blitz again at the end. Mine now tastes the same as the pots from tesco and much cheaper too :)