Highslide only works after all thumbnails are fully loaded

Hello

My website contains galleries with sometimes more than 200 images.
When the gallery page loads it first loads all the tumbnails and that takes some time.
While the thumbnails are loaded the highslide slideshow does not work. When you click an thumbnail it is just opened, but no lightbox or highslide functionality is there. You can even tell it before you click the thumbnail as the “magnifier” symbol does not show up.

If I wait for the page to be fully loaded it works fine.

I guess this is because the highslide script (or other scripts) loads after the thumbnails.

Is there a possibility to load the neccessary scripts before the thumbnails?

Here`s one of my bigger galleries:

http://www.roadtosomewhere.de/laender-bilder/album-japan/bildergallerie-japan-honshu-sued/

Thanks,
Claus

http://wordpress.org/plugins/nextgen-gallery/