Thanks for taking the time to contribute to the jQuery project! Please provide a reduced jsFiddle test case to help us assess your ticket! (in its current form, your ticket does not contain enough information for us to go on as .toLowerCase() is not a jQuery specific method, but rather a JavaScript one.).

Additionally, be sure to test against the jQuery Edge version to ensure the issue still exists. To get you started, use this boilerplate: http://jsfiddle.net/rwaldron/da3nM/. Open the link and click to "Fork" in the top menu.

If you are unable to provide more information or a valid test case this ticket will need to be closed.

I was just coming here after one feature of a website stopped working after updating to jQuery 1.6.1. Firebug tells me:

d.toLowerCase is not a function

(in jQuery-1.6.1-min.js line 16)

This is in minified "function(a,c,d,e)", d.toLowerCase() only appears once, but I am not familiar with the full code so that's all I can contribute for now.

I couldn't yet get it to trigger in normal behavior, a fast solution was Downgrading to 1.5.2 for now.

Later ill give it time and try to provide test cases.

This is a forum discussion around the same issue.

http://datatables.net/forums/discussion/923/x

Check for duplicated element ID's as well in ur dom.

Someone could help us out here by creating a jsfiddle.net test case as was requested

Because we get so many tickets, we often need to return them to the initial reporter for more information. If that person does not reply within 14 days, the ticket will automatically be closed, and that has happened in this case. If you still are interested in pursuing this issue, feel free to add a comment with the requested information and we will be happy to reopen the ticket if it is still valid. Thanks!

#12075 is a duplicate of this ticket.