My first 3d game art. It's Master Jiraiya of the Naruto series. Maya-Zbrush-Photoshop-Xnormal-Marmoset Toolbag, 11k tris, 2k color, normal and specular maps.
You can use overlapping UV's but you want your light map channel (normally the 2nd UV slot) to be uniquely unwrapped. If you don't have a second UV channel created I think it copies your first, which might be the problem you're running into? You can create a second channel on your own or have UDK auto unwrap a 2nd channel…