I bought my house with 5/8" bamboo wood floors recently installed. They have started squeaking more and more lately. After pulling a few up to investigate, it seems like they were glued down to some pretty old plywood. The plywood sub floor seems to be moving around a lot causing the floors to squeak and crack. I can not get to the bottom of the sub floor because it is all I don't think I can salvage the boards because they are glued. Is there anything that can be done about this?