1. Seems to be a lot of currupted files. I took a look at one of the currupted files and saw nothing wrong with it.
2. It never prompts for user name. It surely can set one if you define it.
3. The admin user section is scary looking. Looking for nonexistent files (.htpasswd, etc.)
4. Blank config page... guessing because nothing is really coded in the configuration.php area hehe
Anyway, phpfreechat is awesome so keep up the great work!

EDIT: I downloaded the zip pack