Well, after everything I chose to enable safe-mode then.
I can also confirm that it must be something on my end; I visit a (big and well-known) website using the same scrolling engine as this template, and it doesn’t work there as well.
Maybe it has something to do with the fact that I actually meant the non-WP edition. I’ll kick a similar topic in that forum or post a new one :) Thx anyway!