As I understand it wood usually loses moisture content during steam treatment. Yeah, that's counter intuitive, but that's what the 'experts' say. The surface of the wood gets wet, but the interior loses moisture. Still, as sailordad mentions it is a very good idea to wait a few days before stressing the wood.
The problem is that one end of your bow is weaker than the other. This may be something inherent in the wood, but it may be that you simply left a little more wood on one end than the other. Ron