(SOLVED) jQuery Corner Plugin + Lightbox

(SOLVED) jQuery Corner Plugin + Lightbox

I have a problem on a Wordpress website: I gave certain pictures (as elements of the layout) rounded corners with a jQuery plugin. Some posted pictures I want to load with Lightbox (or similar). I have used several different Lightbox plugins for Wordpress (Lightbox 2, jQuery Lightbox, Simple Lightbox etc. etc.) but none of them work. I got some weird version of GreyBox working but FireFox gives an error every time before opening it so that's real shady code.

Problem: as you can see on this page is that I include jQuery for the rounded corners at first but then the Lightbox plugin AUTOMATICALLY adds it's own version of jQuery and they cancel each other out.

I know for a fact this is the problem because I 'lose' the rounded corners as soon as I turn ON the Lightbox plugin. Once that is turned off the nice rounded corners show again.

Tried: several different plugins, changing the order of the jQuery code around, making both the rounded corners plugin and Lightbox rely on one single jQuery statement. Nothing has worked so far.

Thanks in advance!