It asks me to install a plugin, but then the installation fails with the following message.
breaks existing package 'google-talkplugin:i386'conflict google-talkplugin()
Is there anything that I can do?
It looks like you might have a conflict between an existing 32-bit version vs an attempted 64-bit version, or vice-versa. Make sure you all versions of the Google talk uninstalled before trying again.