Forum:Infoboxes driving me insane

Hello. After struggling with MediaWiki for several hours I finally got it to install. Now that it's installed, I wanted to create an infobox for tracking people, places, and things. I more or less want to copy this structure of the pages at The Vault, a wiki for the Fallout game series. They even have nifty layout outlines too: http://fallout.wikia.com/wiki/The_Vault:Article_layout_guideline/Character_article

My problem is that no matter how many different things I've tried (and deleted) I keep coming up with "Template loop detected" at the bottom of my pages, even though I've tried copying and pasting from dozens of different examples I've found.

The latest failure was copying a scientist infobox from wikipedia.

Template for Infobox = http://www.trenthergenrader.com/wiki/index.php?title=Template:Infobox_scientist

Entry for Paul Dirac = http://www.trenthergenrader.com/wiki/index.php?title=Paul_Dirac

I downloaded and installed parserfunctions to see if that would help; it did not. I feel like there must be something simple that I'm doing wrong, but after hours upon hours of trying and failing and increasingly feeling like an idiot, I'm asking for help. In every thread (like this one http://community.wikia.com/wiki/Forum:How_do_you_make_infoboxes%3F) it seems like some poster comes in and magically saves the day, but there's never a clear explanation of what the problem was and how it was fixed.

Help, please?