OK, this can't be that difficult...

It looks like a simple san-serif, but for some reason, I am having a DICKENS of a time trying to ID it EXACTLY. So many fonts (like Avenir) come close...but I am looking for something with the same perfect roundness and symmetry in the O's and the lower e's. Even the counters within the p's and d's look like circles, and aren't off-center, elongated, or squashed. The descenders and ascenders aren't super tall, either.

Can anyone help??