wow so I just installed FC10 (first time linux user) and I am having the same issues.
If someone looks at this and is new all you need to do is Login from TTY (CTRL+ALT+F2) and kill compiz type ps -e to list all processes then enter kill COMPIZ ID
When I do this, I get the error:
-bash: kill: COMPIZ: COMPIZ: arguments must be processes or job IDs
-bash: kill: ID: arguements must be processes or jb IDs.
when I type in "ps-e" how do I scroll to see the title of the process? From what I read compiz doesn't exist. I have no idea what "ID" is.
As I search, is "desktop effects" the same as "compiz"?
edit: i figured it out via the blind method, thanks