I've tried several solutions for printing pages and this is definitely the best I've found so far. Thank you very much!
One wish though:
I noticed that the plugins skips the tables, like here -> http://fr.yoga-laurence-lhermitte.be/les-cours/cours-collectifs/ (the 2 columns within the page are a table and it's totally skipped by the plugin). So it'd be nice if the plugin would include tables, or at least tables content.
I noticed (at least in my case) that in category pages (multi-posts), it takes only the eldest post. All others are skipped.
In fact my way to solve that is to not use the plugin at all and rather use your website. Then I put the given code within a widget. That way, it works perfectly for category pages as well.