Thanks for the help
The plywood sub floor is 3/4 inch thick. It looks like they glued down the first 5 rows of bamboo then started nailing them down from there. I think I am going to drill a few holes in the bamboo and attach the sub floor to the joist better. Then fill the holes with a plug made from left over boards. A stud finder on the floor below should help me locate the joists. I was also looking at using a Counter-Snap Kit to help hold the floors down better. http://www.worksavers.com/countersnap.html
The floors have been in for over a year, so they should be pretty acclimated.
Does this sound like a good plan?
Has anyone used the counter-snap kit before?