Hi,
1.8 has a lot of changes ‘under the hood’, I am glad that it is fine.
as for 1.7 the general structure of page wrapper and nav sidebar isn’t overly complex.
Sorry for asking about this, but sometimes the easiest solutions are the Best.
Did you try to clear your browser cache or use different browser?
Perhaps you could spot some issues in your web server logs or chrome dev console?
Failing that you could try to set up a demo CMS with Spring Signage and see if everything will be fine
After that we should know where the problem might be (or at least narrow it down)