I think that's rather due to a local version of glib built to /usr/local or something like that
Could you copy a "ldd /usr/lib/libgconf-2.so.4" to a comment?
** Changed in: gconf2 libgconf2-4 (Ubuntu)
Status: Unconfirmed => Needs Info
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Symbol Lookup Error during Dapper Upgrade
https://launchpad.net/bugs/41219