I had the same problem with another m-audio interface - the fasttrack pro. I couldn't get any signal out of any mics (i bought another one because I thought the first one was stuffed!) until the dial was up full, then it would spike. I found a few theories online about why, but no solutions unfortunately.
As well as what Ski says I suggest you try the mic out on another type of interface if you can. Then at least you'll know if its the mic or the interface, and can make some decisions from there.