No, he only has one account. It is just that your browser is incapable of displaying his name in certain situations, like many other browsers.

Regardless, it if it displaying as "Stilet?" that means either the T or an O is being interpreted as something else (as there is only one question mark), and it could be why the text is bold. Just a guess.

No matter the reason, it is just a local browser display thing; there is no way to make the sidebar information bold.

~ Traft