New JQuery 1.5 breaks good old image lightbox... why?

Currently a (bought) JavaScript lightbox code works on my website that does work perfectly, only on older jQuery libraries like 1.3.2 and 1.4.3, but not on newer builds like 1.5

The problem on the new jQuery libraries is, that upon clicking a thumbnail the screen first goes into the dark mode but the lightbox never shows up, somewhere during that process it stops. This happens only if I load the new jQuery libraries, which I do prefer to use since all rest of my site works faster it seems with the newer builds.

Any hints Where I should be looking for / where to find Jquery differences?

Your ideas are much appreciated.

Line 73 - "SWFObject is not defined"

Edit: http://blog.jquery.com/2010/11/11/jquery-1-4-4-release-notes/

BACKWARDS-INCOMPATIBLE CHANGES IN JQUERY 1.4.4 The .width() and .height() methods no longer return 0 when inspecting an element hidden using ‘display: none’. To determine if an element is hidden, always use .is(‘:hidden’).

Your script is full of height() == 0 or width() == 0 or Maths calculations with width() or height(). My best recommendation is to stick with jQuery 1.4.3 or rewrite the plugin \o/