Tested on both Mac and Linux. When editing a description in the column view (either in the task editor or the task viewer), the text entry box is way too narrow. It should either use the full width of the description column, or resize to match the text (up to a maximum size of the entire viewer maybe, or maybe to a maximum of the description column width). Currently, it is too narrow in some cases to even show an entire long word. It seems that it might be an issue of whether the text is multi-line or not, but I'm not sure. It's never very wide, but sometimes it is a little wider than other times.
re-opened at https://github.com/taskcoach/taskcoach/issues/57