Can't change default passwords -asterisk service stops

I have found that this has happened to some other users to but as yet I have not found a solution.

  1. I have change the Default ARI Admin password and yet still get a warning that it is using its default password.
  2. Whenever change the Default Asterisk Manager Password in amportal.conf and manager.conf, FreePBX shows that my Asterisk server stops running. I have even tried simply deleting one character of the end or the passwords i.e. making it amp11 (instead of amp111) and then rebooted but it still goes down. The moment I change it back to amp111 and restart the asterisk service it all comes right.