The bug: col-resize and row-resize cursor icons are incorrect. col-resize should be a horizontal double-arrow, row-resize a vertical double-arrow, but not the other way around. How to reproduce: Start gtk3-demo (installed by gtk3 package), select "Cursors", "Resize & Scrolling" -> click on 'col-resize'/'row-resize' (second and third) icons. Or open /usr/local/share/icons/Neutral++_White/cursors/col-resize (row-resize) with gimp/your favourite cursor viewer. How to fix: Just rename col-resize -> row-resize and row-resize -> col-resize.