In Beta 2.0 R2529, clicking on the avatar image in user admin links to "//administrator/index.php?option=com_ninjaboard&view=person&id=userid
Instead, it probably should link to /index.php?option=com_ninjaboard&view=person&id=userid
As a side note: I find it a bit awkward to link to the front end in the first place. Before noticing this bug, I assumed clicking the image would do the same as the "Change image" link that sits right next to it.
Edit: Should I report things like this here, or rather on GitHub ?