It seems that the visual editor can glitch a bit when it initially renders a template. Yet when the template is altered without changes this is corrected. (Firefox 22, Mono skin)
'''Steps to reproduce:'''
- Navigate to https://en.wikipedia.org/w/index.php?title=User:Excirial/Playground/Content&oldid=562754871 (Historical revision of my sandbox)
- Edit the page in the Visual Editor. You will immediately notice that the template isn't correctly displayed.
- Enter the template setting screen and just select "Apply Settings".
Once that is done, the template is rendered correctly. Note that the same template was initially added trough the visual editor itself and displayed just fine. Only when you open an already saved page it seems to glitch a bit (Until the settings are applied without change - somehow that corrects it). The page reports no changes after applying, so it seems this is just a rendering issue.