Comment 4 for bug 501601

An easy way to reproduce this is to just do:
printf "\003\n\x1A\n"

This shows than when receiving these characters, gnome-terminal tries to print them, instead of ignoring them.

When doing: printf "##\003##\n", gnome-terminal (and thus also terminator), will print 2 hash characters, then the unicode square, then another hash covering the 2nd half of the unicode square (because the square is seen as a single character, though it takes up the space for 2), then another hash.

Xterm, screen and tty (TERM==linux) the same command will just print 4 hash characters.

If this might help, I have to mention again that running a screen session in gnome-terminal it works as intended. I don't know if this is the doing of ncurses or a terminfo configuration, or the separate utf8 encodings installed with screen.