After the last lot of updates (some of which were cinnamon updates) I lost
touchpad functions, browser functions, all sorts of mess. I reinstalled
Trisquel, set everything up, installed Cinnamon and it was the same. So, I
reinstalled Trisquel and went straight for the Mate desktop. All is OK again.
I'm not technical enough to know why or how to invesitage and with the choice
of alternative desktops, Mate is the easiest option (I prefer it to Cinnamon
anyway).
I just installed Mate per the instructions on their webpage for Ubuntu 12.04