I know a few and they said this...
Go to the nokia website -
http://www.nokia.co.uk/nokia/0,,18122,00.html and the support area you should be able to send the settings to your phone as a service essage and this should help download the missing files.
if not: scan the nokia forum
http://www.forum.nokia.com/main.html worst case there is a firmware reset / factory default but that is a bit drastic, the code is....*#7370#
P.S. the 6600 is a bit of a buggy phone
Paul