after many time I've updated my 2.5 pull request  creating a new
pull request for joomla 3.0  .
These changes on 2.5 works perfectly.
Replicating all the changes from 2.5 to 3.0 lead to 404 error for home
page, following call stack
# Function Location
1 JSite->dispatch() /Users/gabriele/Sites/tst/index.php:42
2 JError::raiseError() /Users/gabriele/Sites/tst/includes/application.php:208
3 JError::raise() /Users/gabriele/Sites/tst/libraries/legacy/error/error.php:242
This error appears with "SEF" equals to zero and equals to one.
Administration side works without problems.
Can anyone help me finding the source of this problem and testing
these changes ?