how about murphy oil soap? I don't have hardwood floors, but this is what I use on all my woodwork and furniture... my mom has also used this for years...
http://www.colgate.com/MurphyOilSoap/home
eta... under the problem solver is says...
Wax buildup on improperly cared for floors
Solution: Remove the old wax with Murphy® Oil Soap. Several applications and some elbow-grease may be required. Then make sure that the proper finish is intact, to preserve the life of the wood, and re-wax as appropriate. If in doubt, consult a wood care professional.