5
Yep I tried that. Now this is what is weird.
I downloaded the 2.5.0 Alpha and uploaded it via firezilla FTP. Just to see if I could get it installed, I moved everything to my root and tried running the checksum.php file. IT was CHMOD to 777. When I tried to access it, I got the error about file permissions! So I copied the content inside the file to the clipboard, created a new file called "check.php," pasted the checksum.php content, and saved it. This file ran with NO problems.
I hope this helps!