This is the reason - while using PdUp/PgDn for scrolling, you move cursor, loosing current word selection. I have no idea how to fix that without breaking other things.
ohhh...of course :blush: So Issue 2 is the only one I can re-produce.
@stosunek: do you encounter the problem if you only move the cursor on a word or click once on it, or do you encounter the problem if you double-click on a word (and so select it)?