General discount isn't showing on pdf

I’m running version 1.4.6 of invoice plane. I’ve been running it for a while and just noticed that when i discount the entire invoice by an amount (not percentage, although i haven’t tried that) the total bill shows the amount as correct but no line shows up that says what the discount amount was. Is there any way to add this on a pdf?

Also, I was going to update but it says no update available (even though the notes below show there is version 1.4.10. ) How do i go about updating?

Wiki page about updating IP:

Wiki page about customizing the templates: