getting a lantern to light properly

I downloaded http://www.daz3d.com/winter-fantasy-for-genesis-3-females and I can't seem to figure out how to make it work properly. I'm trying to set up a dark scene where the lantern would light up the room but I'm doing something wrong. I changed the surface of the glass to iray clear thin glass and I changed the flame to emissive since the lantern produces no light as it is. With those settings it's just a mess and the candle next to the flame gets bunch of sharp noise instead of displaying the surface. Any idea how I could set this up to look realistic?
Comments
Is the glass two-sided -- two surfaces, one pointing in and one out -- or a single surface pointing out? I've had weird Iray results with light passing through 'one-sided' glass. If the glass is 'one-sided,' try duplicating those polys, moving the duplicates inward perhaps 2mm, and flipping their normals to point inward. Then the flame emissive will reflect normally inside the lantern.
I hope this helps,
Crissie