double-width characters mess up display

there is an issue with the display of double-width characters (like chinese) that i don't know what to make of. the characters show up as boxes, which is fine (i can't read them anyways :-) but they have the wrong size, which messes up the display of the characters behind.
in the screenshot, on the left is a regular gnome terminal, and on the right is pharo with pterm and playground.
pharo can display chinese characters. though maybe it doesn't work with monospace fonts: http://forum.world.st/Chinese-Character-Data-td4843635.html
Yeah, this is a known issue that i dont know how to fix it yet, (it seams something related to Pharo). Even if the characters are displayed correctly with Unifont, the tabs are not aligned correctly
