Okay so back in August I downloaded Lion and installed it on my MacPro Quad 2.66 XEON with 5gb RAM. It seemed to install fine until I installed some updates right after and the MacPro froze on the grey Apple screen with the little status bar stopped. Contacted Apple and the guy from apple told me to put my Snow Leopard disk in and run verify permissions and Repair Permissions which after the fact I found out from Apple that he should not have done that since the repair is different on Lion than on Snow leopard. Nothing worked so I had to do a erase and install of Snow leopard. So a few months went by and decided to try it again...Still the same result. Locks up on grey Apple boot screen. Did find out I can do a "dirty" install over it using Snow Leopard and I lose nothing. All of my programs and stuff is still there. So after reading about others having issues I have reset the PRAM, I have taken my other drives out and tried to install, I have tried to install on another blank drive on my Mac, I have taken out my added RAM, swapped other RAM ,tried to install using a Lion install disk, tried to install using a Lion Recovery USB from Apple, tried using the Recovery HD that Lion creates and still I get the same result. Spoke with Apple Senior Advisor who sent me a configuration tool which I ran and sent him the report that is created. (haven't heard back yet) Anyone else have an idea what is going on or had any issues such as this? Any ideas on a fix or something else to try? I am ticked because I have been a Mobileme user for a years, I have a iphone running IOS5. These all work together if you have Lion but won't if you don't I have do too much money invested for this not to be fixed.