Macrumors has a list of incompatabilities with Leapord here:
http://guides.macrumors.com/List%3AA...e_with_Leopard
I am having problems with Time Machine but it may be tied into the external hard drive I am trying to use.
The thing that I find annoying is the lack of a manual but that seems to be a problem with a lot of software. I suppose I will have to wait for the inevitable "Missing Manual" publication.