I have a MAC running OSX 10.3.9, with specs: Dual CPU G4 1.25Ghz + 1.75GB ram If I am going to upgrade OSX to Leopard 10.5 (not clean installation), is it possible to do? And if possible, will it give me trouble running applications previously installed on 10.3.9? such as conflicts... or do I need to upgrade the MAC machine to run Leopard? Any suggestions? Thanks in advance.