Just tested this in 3 different apps (default mail app, evernote and RedditHub). In all cases I intentionally misspelled a word which gave me the squiggly red line. In windowed mode when I right clicked on the misspelled word nothing happened When I switched the app to full-screen and right clicked the word I got the expected pop-up with spelling suggestions. I then switched the app back to windowed mode and again the pop-up wouldn't display.
