Thanks Daixiwen for your reply.
I have found out what is happening thanks to an earlier thread of mine. It appeared I had enabled both Altera's experimental tse driver and SLS driver, and that was causing the trouble.
Now I can start the device, ping it from my laptop etc. I was able to start boa webserver as well, and run cgi script.
Now I need to go one step further and be able to modify the page that is displayed in my web browser when I type in my board's IP address in the address bar.
What are the files that need to be modified ?