Most likely, jQuery.noConflict was called somewhere in the page so that the $ variable could be used by something else. If you are including a lot of plugins, one of them may have done it.
- [jQuery] $() and Object doens't support error skellish
- [jQuery] Re: $() and Object doens't support error Dave Methvin
- [jQuery] Re: $() and Object doens't support error Scott Kellish

