I've experienced the shrinking with gnome-terminal 3 too. When you open a terminal or a new tab the window shrinks rapidly but by one character at a time, so it looks like some sort of animation effect. I think it may depend on the font used and/or window manager, whether it shrinks at all or in only one direction or both. I've been working on a GTK+3 branch of roxterm and that does it too. It might be a vte bug, a gtk3 bug or a bug common to gnome-terminal and roxterm. I'll have another look at roxterm and try to narrow it down.
Managing the size of multiple VteTerminals in a GtkNotebook has long been a problem, it looks like it might have got worse with the gtk3 stack :-(. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org