It is a problem. For some things I'll wrap a name or call-to-action in a span tag with a class that sets white-space:nowrap.

For headings, you can add an "orphan protection" script that dynamically inserts a nbsp between the last two words.

It really depends on what you're trying to do? I'm wary of doing too much here, because We need to factor so many different screen sizes etc.

p.s. I hadn't even heard of en and em spaces in html, thanks Mattan.

As a simple workaround you could group the circles into columns, and then do the alignment. Just tried doing so; it works.

What a bug! The result is kind of amazing.