Prevent initial expansion (mootools)

First: I am new here. Please let me know if this post is in the right place.

I am building this site: http://www.blog.halfdane.dk
I have based it on the theme “Minimalist” that apparently uses something called mootools for the expand/collapse stuff.
When initially loaded (or when reloading) everything briefly expands and then goes to rest in collapsed position. I would love if this initial expansion did not happen. Is that possible?

Thanks!