Raspberry Pi problem

Hi There,

I just updated the Raspberry Pi FR firmware.

While updating I overwrote the fr24feed.ini

pi@raspberrypi ~ $ sudo dpkg --configure -a
Setting up fr24feed (1.0.14-7) ...

Configuration file `/etc/fr24feed.ini'
==> Modified (by you or by a script) since installation.
==> Package distributor has shipped an updated version.
What would you like to do about it ? Your options are:
Y or I : install the package maintainer's version
N or O : keep your currently-installed version
D : show the differences between the versions
Z : start a shell to examine the situation
The default action is to keep your current version.
*** fr24feed.ini (Y/I/N/O/D/Z) [default=N] ? Y
Installing new version of config file /etc/fr24feed.ini ...

now when I run the setup I get :

ERROR: config file '/etc/fr24feed.ini' is not writable. Please check that file permissions are correct!

tried changing the file permission, but it is not working

chmod: changing permissions of `/etc/fr24feed.ini': Operation not permitted


could someone help me out.

Thanks