A forthcoming update to version 2.0 will, by default, allow some adverts to be displayed on certain webpages.

https://adblockplus.org/en/acceptable-ads

It is just a case of going to the preferences and turning them off again, but I'm not sure many would go and check the prefs after an upgrade so am posting this to bring it to your attention.

Thanks for the notice

Yep, thanks for the heads-up