tiny_mce_plus plugin doesn't insert image. I don't even know how to debug it.

Hi,

I am using tiny_mce_plus (http://github.com/devon/tiny_mce_plus) for
my rails(2.3.2) app.
It works fine except that "Insert" button doesn't insert the selected
image.
When I click 'Insert' button nothing happens.
I don't know how to debug it.

Sorry, my explanation is not sufficient.
Does anybody have the some problem?

Thanks.

Sam