Is there another synaptic already runing somewhere? Can you open a termianl and start:
$ gnome-app-install
in it and tell me what output you see when you click "Apply"? Does it print something like: "Another synaptic is running. Trying to bring it to the foreground" (or do you have that in your .xsession-errors file)?
Is there another synaptic already runing somewhere? Can you open a termianl and start:
$ gnome-app-install
in it and tell me what output you see when you click "Apply"? Does it print something like: "Another synaptic is running. Trying to bring it to the foreground" (or do you have that in your .xsession-errors file)?