I have OS 10.5.8, I want to upgrade to Mountain Lion so I can use iCloud so my i5, iPad and iMac can all talk. So, seemingly, I download 10.6 successfully, BUT every time I try to install OS 10.6 (so I can then download Lion) I get an error message saying in order to install OS 10.6 i need to install 10.6, it's totally weird and it wont let me do it? Has anyone ever experienced something like this before?