WP jQuery Lightbox version 1.2.1 was working fine with WordPress 3.1.1.
But after upgrading WP jQuery Lightbox to version 1.2.2 I've noticed a strange bug.
When opening a picture, the picture opens normally, except that the webpage I'm on has a much bigger scroll bar (before clicking on the picture there was no scroll bar). So when I "page down" through about 5 or 6 times worth of blank space there is the same picture at the very bottom of the webpage.
Tested in Firefox and Chrome.
Downgraded back to 1.2.1 and it works like normal again.