Sulfur smell...

Friend of mine just brewed his second AG batch. A Belgian Wheat. His first batch he brewed a week before this one went fine, but this one has an overwhelming smell of sulfur. He used a Wyeast 3608 smack pack, and the manufacturers website said that there may be that smell, but should go away after a few days. It has been there for a couple weeks. All I know is he got the recipe from HBT, and he got horrible efficiency, 48% (not sure why). It also tastes like a 'mouthful of matches'
I've never heard of such a thing, has anyone else? Any ideas what happened?

I've never had a Belgian Wit go sulfur and stay there on me. I usually use WLP300 for my wits. If its still in the fermenter, I would let it go on the yeast a little longer and maybe warm it up a few degrees to encourage the yeast to clean up. The matches taste is in line with sulfur if you look at a flavor wheel...