A:
There are any number of cleaners on the market, found in supermarket that say they are for hardwood floors.
Your safest approach is to purchase a cleaner created by hardwood flooring manufacturers or floor finish manufacturers. This can be purchased (these products, as far as I am aware, are all basically the same) from local hardwood flooring retailers or a big box store that sells hardwood flooring. Best bet is the Hardwood retailer who specializes in hardwood. I use "squeaky cleaner" manufactured by Basic Coatings. See their web site: www.basiccoatings.com.
Mirage cleaner is another one.
It sounds likely that the cleaners being used on your floors are leaving some sort of film on the wood surface. This can create the situation you are describing and can make buffing and recoating in the future impossible to achieve due to adhesion issues.

