Hi Rob, thanks. I actually haven’t spotted any extra-indexing problems in my Webmaster Tools account so far. I was just concerned about the fact that the same (or very similar) content was appearing on several recurring pages under slightly modified URLs.
But although this may not be a problem, I still found a fix for this. Since I use Yoast WordPress SEO, what I do is that I create an event without setting any recurrence for it and then publish it.
I then edit it and paste its normal URL in the “Canonical URL” box of WP SEO on the Post Edit page, then set the event’s recurrence, and update the event.
This causes all recurring event pages to have the main/true event page as their Canonical URL. So far, this works pretty well.
But thanks for the help!