Comment 31 for bug 42178

This bug is so old that its status should be changed in Won't Fix.

I don't see it, but it'll be a good reason if the developers do not want to implement the system-wide lock.

However, this behaviour should be clearly stated in the man synaptic(8) where it says instead:
> Synaptic is a frontend for the apt package managent system.
> It allows you to perform all actions of the command line tool apt-get in a graphical environemnt.
> This includes installing, upgrading, downgrading and removing of single packages
> or even upgrading your whole system.

And in the help menu of Synaptic, too. In the section "To Lock a Package to the Current Version (Debian only)" there is not enough emphasis on the fact that the actions aren't disabled system-wide