Solid Hardwood, Engineered and Laminate Flooring - glue or staple?

I recently ordered a Lauzon Santos Mahogany engineered floor. The floor is being installed over a crawlspace. I am in the process of adding a layer of 1/4" plywood over part of the room to bring it up to the level of a section of the room with a particle board sub-floor that was under tile. The floor can be stapled or glued down. I was planning to staple the floor down, because I thought that gluing was mainly used over concrete or vinyl. However, I was talking to the flooring person at a local Loews, and she told me that I should glue down the floor because it would be more stable. So now I am questioning what method I should use. What would the advantages and disadvantages of stapling versus gluing the floor? I am getting conflicting information from various flooring people that I talk to.

Thanks

You cannot lay that material over particle board. It needs to be replaced (or just removed) You probably have a good subfloor under it.
Its your choice on the the glue or staples. All things considered, I would use staples. They will both hold fine but that floor will not be there forever and somebody, someday is going to have to remove it. Environmentally, staples is best too. The most movement will be the Santos Mahogany(good choice) and neither choice will have any effect on it.

Thanks for the info. I was hoping to avoid tearing out the particle board. It's 3/4" thick and will need to be replaced with plywood. At least it's not a very big area to tear out.