You can find a full audio recording of Romney's immigration statement over here.
The New York Times has more information on the crashing silence coming from Romney's campaign. The reason he's afraid to say anything is that a Romney win this November would have to go through Florida, and he can't win Florida without some larger share of the Latino vote than he currently has. (According to the 2010 Census, Florida is 22.5% Latino.) But Romney can't come across as soft on immigration or else small numbers of Republicans everywhere will abandon him. So he's saying nothing and hoping that the issue will just go away. We'll see how that works out for him.