I recently removed a Sim card from an N900 that isn't going to be used as a phone.

Now it gets a message on boot saying "SIM card registration failed." How do I get rid of the message?

If I go into Settings, I find that under Phone/SIM card, PIN code request is NOT checked but there are four asterisks, I imagine from the old SIM. I can't delete them. If I could, i imagine the error would go away?