Michael and I don't have any different opinion here at all. You are complaining about root/.synaptic/tmp//tmp_cl - which is owned by synaptics - not about the /var/cache/apt/archives/partial or another apt owned directory.
A directory inside your (well, root's) home directory is a different case altogether: It *should* be owned by you, not by _apt.
Michael and I don't have any different opinion here at all. You are complaining about root/.synaptic/ tmp//tmp_ cl - which is owned by synaptics - not about the /var/cache/ apt/archives/ partial or another apt owned directory.
A directory inside your (well, root's) home directory is a different case altogether: It *should* be owned by you, not by _apt.