Comment 20 for bug 1330198

  Thanks for confirming! Sorry, you're right, I had it backwards. NumLock on, scrolling works.

So now the questions are (not asking you, just putting these thoughts somewhere):

1. Why do Gtk apps care about having NumLock ungrabbed?
2. Why does ungrabbing any other modifier in conjunction with NumLock not allow unfocused scrolling?
3. When NumLock is ungrabbed, why does turning off NumLock not allow unfocused scrolling?
4. Why does ungrabbing buttons with AnyModifier work for scrolling regardless? This should be similar to point 2 above, but it works - it just breaks using a modifier with the vertical scroll wheel.