Last Friday, I was struggling with a strange issue on a Magento site I was working on. It worked fine in everything except IE – IE8 spat out lots of errors about certain lines in the Prototype and jQuery libraries, and refused to run any other code, which made the site unusable.
I soon decided it was worth updating jQuery top the latest version, as the one shipped with the jQuery Lightboxes plugin was several versions behind. (To upgrade, you’ll first need to disable the plugin’s version by going to the Magento dashboard, then System -> Configuration, select the ‘MAGEPSYCHO EXTENSIONS’ -> ‘jQuery LightBoxes’ option on the left, then set ‘Include jQuery file’ to ‘No’. To then include jQuery, add an ‘addCss’ action to your local.xml file – search online if you don’t know how to do this.)
Hopefully this will prove useful to someone!