There is no default action in the Software Updater Settings to Ignore.
This is reflected in the Software Updater interface. Whilst you will see Blue text saying Ignore Updates, that is a clickable link the user can click to Ignore Updates for that particular application. To the right of that is the indication that the application/program is Up to date.
So I don't know if this is a misunderstanding in that you think that they are being ignored ?