nicEdit error "obj is null"

[eluser]tfncruz[/eluser]
Hi!

I'm trying to integrate nicEdit with codeigniter.
If I use

Code:

bkLib.onDomLoaded(nicEditors.allTextAreas);

everything's fine.
But, since I want to configure the buttons, if I use, for example,

Code:

new nicEditor({buttonList : ['fontSize','bold','italic','underline']} ).panelInstance('nic');

it returns the following error: "obj is null"...

Any ideas?!