Problem integrating Zimlet with JQuery

Hi guys,

I'm trying to make an integrated Zimlet which creates a custom toolbar button.

I downloaded the example of integrated Zimlet at : ZCS 6.0:Zimlet Developers Guide:Examples:Adding Toolbar Buttons - Zimbra :: Wiki

It worked normally until I modified the zimlet definition file to use JQuery:

<include>jquery.js</include>
<include>com_zimbra_example_toolbarhook.js</include>
<handlerObject>com_zimbra_example_toolbarhook_Hand lerObject</handlerObject>

After deploying the zimlet,I keep getting this error and I don't have a clue why it happens:

Uncaught TypeError: Object visibility:hidden;border:0; has no method 'insertBefore' Zimlets-nodev_all.js:1169

When I switched to dev mode,it worked normally.

Any help would be highly appreciated,thanks.