The problem of Admin General not showing up happens frequently, usually being due to too low PHP memory_limit. What is yours? If it's OK, you could also try 1.8.1.
One thing I wasn't sure to understand is did this page ever worked (and then broke) in your install? I'm asking because you say "changed name of homepage ".
Thanks for the good description, maybe you'll get a faster answer asking first on IRC #tikiwiki.
It's a pleasure if I could help.