iTunes won't import new files

[Odysseus]

Help!
Suddenly, my iTunes refuses to import new files. I can no longer add new files to my library. Nothing happens... whether I drag files into the library or use "file>add to library" command. How did this happen? Is there a way to persuade iTunes to let new-comers in? Still have plenty of rooms in my HD.

[Kelvin]

Have you tried fixing permissions? Have you deleted the preference file of iTunes? These two things normally fix almost all my OS X problems.

[Odysseus]

Permissions? But I am the only one who uses this computer and this is my first time to encounter this problem. As regards, preference, do I delete it?

[Kelvin]

Yup it doesn't matter if you're the only one using your computer.

Yup delete the preference file (make sure iTunes is not running), iTunes will make a new one when you run it.

[Odysseus]

Thanks... iTunes is hospitable now.
some bad spirits must have possessed it this morning.