Hi,

When using vector selection tool, you need five mouse click on the canvas to edit a text box: 
1. a first double-click switch from the VectorSelectionTool to the TextCreationEditionTool
2. When using the TextCreationEditionTool you need a triple click hover the text box (the dashed box switch to dark red) to get the pop-up.

Despite my chilhood training and long experience in point-and-click role-playing video-games, I still can't make the gesture smoothly even less with a stylus in hand. :-)