I get all errors (404) and the like via logging and I noticed alot of thickbox errors.
It occurs when and if a link is outside the main directory. including author, category, tags, pages etc.
Might want to change it on the next SVN. REmove the .. (double dots). I did and the errors occur no more. The issue at hand is even a minor like this one causes enough error to add 2 or 3 or more seconds to your load time and produces errors that may flag your site in search results not to mention a reason why he pix i needed any who.
at line 8 nd 9
var tb_pathToImage = "../wp-includes/js/thickbox/loadingAnimation.gif";
var tb_closeImage = "../wp-includes/js/thickbox/tb-close.png";
var tb_pathToImage = "/wp-includes/js/thickbox/loadingAnimation.gif";
var tb_closeImage = "/wp-includes/js/thickbox/tb-close.png";