Yep - unfortunately this is an issue with Firefox - for some reason they throw an uncatchable warning that we can't prevent (they should be throwing an exception that we can catch).

Has a bug been reported to Firefox regarding this issue?

Replying to [comment:1 john]:

Yep - unfortunately this is an issue with Firefox - for some reason they throw an uncatchable warning that we can't prevent (they should be throwing an exception that we can catch).

Firefox 3.6.11 and IE 8 both have this issue with jQuery 1.4.3.

I had to rollback to jQuery 1.4.2.

This needs more attention.

I agree, this needs more attention as it does not occur with 1.4.2, but it does with 1.4.3 which means something changed in the jQuery code-base that is causing this. I don't rule out that FF could play a role in this but testing with the newest FF and 1.4.2 this exception does not happen.

Replying to [ticket:7291 csnodgrass3147@…]:

Using Firefox 3.6.11 and jQuery v1.4.3, the error console gives the following CSS warning: Warning: Unknown pseudo-class or pseudo-element 'sizzle'. It is given this even on a blank page that just includes the library.

Replying to [comment:4 Diemuzi]:

I agree, this needs more attention as it does not occur with 1.4.2.

Firefox or not Firefox. We had 'charcode' warning and now this. No one wants sites with warnings. jQuery team should reconsider its support for FF. This doesn't look good and may even discourage some people from using this framework.

Can you test this with 1.4.4rc2? Thanks!

Using the latest version from GIT (which I'm guessing is 1.4.4rc2) it does seem to be fixed using Firefox version 3.6.12.

That's great news. The ticket can remain closed. :D

Opera 10.63 with 1.4.3:

HTML style attribute
Unknown pseudo class
Line 1:
  #__sizzle__ >ul:hidden
  ----------------------^

waiting for 1.4.4

Warnings don’t mean anything. When you use jQuery’s custom pseudo-selectors, you are knowingly passing an invalid CSS selector. If you don’t want to see warnings about it, never ever use any of the custom pseudo-selectors. Otherwise, ignore it—it’s normal, and it doesn’t harm a thing.

Warnings do mean something...

And in this case, the warning occurs simply by including jQuery, whether or not you use sizzle.

However, this problem seemed to be fixed with the latest version and so it's a moot point now.

Well, true, with 1.4.4 *this* warning was gone, but instead we've got:

Warning: Unexpected token in attribute selector: '!'.

And it's the same with 1.5 :-(

Last seen in FF 3.6.13

I can't help but think these issues are related. And I think to recall that it was about the transition to 1.4 that these mysterious browser warnings started.

A site may continue to function with warnings, but if they can be eliminated, they should be. Another side affect of all these warnings seems to be that the page loading icon perpetually runs in the page's tab. If I'm a user, I'm used to seeing a page loaded icon once the page is complete, and having the icon and status bar telling me that it's still loading is unsettling. Am I free to proceed or not? After getting rid of the code causing the warnings, the page loading appears to complete without a hitch.

well i have

Unknown pseudo class
  [id='__sizzle__'] :input,a
  ------------------------^

with latest version of opera 11.52

and jquery 1.6.3

Can't understand what can cause this error. It keeps bubbling in the error log.