I maintain a Firefox extension that includes jquery. When some pages are loaded, jquery pops up a javascript error that says "Error: div.style is undefined".

This is caused by lines 834 and 835 of the uncompressed jquery 1.4.2, which look like this:

div.style.display = "none";

div.innerHTML = " <link/><table></table><a href='/a' style='color:red;float:left;opacity:.55;'>a</a><input type='checkbox'/>";

Apparently, div is not initialized in some circumstances. If I comment out these 2 lines, the problem goes away.

If you want to reproduce it, download/install this FF extension: https://www.surfcanyon.com/search/surfcanyon_sc.xpi. Once the extension is installed, load this page: http://bit.ly/dsgsg3

The extension uses an older version of jquery, which has the bug. If I replace that older version of jquery with 1.4.2, the bug is still there, which is why I'm logging this as a 1.4.2 bug.