javascript error when asking a question

Hi,

We are having a problem with Q&A every time we go to http://eugadget.com.br/questions/ask/, we get the javascript error: "Uncaught TypeError: Object [object Object] has no method", apparently it is coming from the TAG text box.
To replicate the problem on our website, go to http://eugadget.com.br/wp-admin and log in with *edited for content*
After log in go to: http://eugadget.com.br/questions/ask/

In case you need more information please let me know.

Thank you in advance for your attention!

Regards,
Maick