I think I'm having some of the issues others report with jquery lightbox and IE, transitions are rough, no transparency - background is black. Works fine in Firefox (v3x, v4x).
Checking the site the author has linked to, http://game.hgo.se/blog/motion-capture/ - here his lightbox plugin appears to work just fine in IE. I checked the version of jQuery this site is using, v1.4.2.
My site is making sure jQuery v1.4.4 is downloaded, not older version. Wonder if this might be related to why some of us are seeing problems with IE and jquery lightbox?