I just shot one (11-10-06) that my arrow hit a branch and hit low in the gut, more rear third and low. I waited about 8hrs before I started tracking him and when we found him, he was still alive and needed a second shot. He only went about 100yds and bedded in real thick cover, it was a tricky bloodtrail that doubleback, but we found him.He was only 50yds or sofrom where I shot him. I hope you have the same results since you are doing the right thing by letting him sit overnight.
Here is the link with the pics of where he bedded, it was only visible from one side.
http://www.huntingnet.com/forum/tm.aspx?m=1796838