Hi James, I am going through the same thing? I have a mac pro 8 core and Snow Leopard as my OS and am trying to install Maya 2008 Unlimited and I heard that older versions such as Maya 2008 have some problems installing on Snow Leopard, why? I did not find out yet. Please let me know if you come up with any answers.
Maya 2008 is officially supported on OS X 10.5.2
http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=14959955&linkID=9242259
Having said that, please try the solution provided in the following tech note TS1090715 or download Pacifist 2.6.4 and install Maya core package with it.
Hope this helps.