Thanks for your reply.
I tried first to disable all other media but youtube, but it didn’t work.
So I deleted the plugin and reinstalled it and it worked. Strange because I’m pretty sure I haven’t edited it at all… Anyway, it works, so thank you!
I’m not sure to have understood your first point, even though I know you’re trying to help me beyond your plugin: The first error causes your analytics code to fail so you might want to fix that (remove the backward slashes!) Could you please tell me more about it?
Many thanks for your response and for your great plugin!
Roger