I've used paint before, esp latex, that smelled as if the water base had molded or something. What brand is it and was it fresh from the store? Do you have any left in the can to smell?

The company teated the paint and it was fine. Additionally, I primed and added a new coat if new paint. I was tild the primer would mask any odor.

Oh dear, I hope you find the cause. Was the paint ALL you did to the room? Have you smelled the paint in the can? It could test fine but still smell funky to sensitive noses. Did you use KILZ or similar as your primer?

I once used a previously opened can of paint to paint a bedroom in a rental we owned. After finishing, there was such a smell. I ended up having to prime the walls with Kilz and repaint. It was fine after that.

Dead mouse in wall?