Your shelf is already saved
To add it to the new version just go the the shelves and pick the option to load a shelf, this will then load and save it in your new version of Maya.
Sorry about being vague, but I am not in front of a copy of Maya and I am no sad enough (yet) to remember the menu commands :p
Chris (formerly R@nSiD)
When the power of love overcomes the love of power the world will truely know peace - Jimmy Hendrix
Winner SM VFX Challenge 1
3rd Place SM SteamPunk Challenge (May 2007)