its weird why it couldnt chnage, in mine it change, i had upload phone icon, replace it go to /usr/share/icons/symbian-anna-icons/64x64/hildon using file box find general_call.png open it if it has the blur one, try replace it with mine which has uplod.

in mine looks alike this one, what do think with next terminal.
anyway before u ask why facebook icon look like this because it was related to sociality this icon is general-facebook,,
thanx for reporting.