Callback problem from invisible div

Hi,

I am currently working on a small interface, and I am trying to replicate the example:
https://dash.plot.ly/sharing-data-between-callbacks example 1

to make it simpler I am just using the hidden div to dispatch the value from the dropdown,
my first callback update successfully the children value of the hidden div but the second callback
receive none type data.

I also notice that my app is firing the callbacks at startup without the drop-down widget to be manipulated.
Another thing I notice is that the placement of the hidden div can also be a problem, in my case my app has multiple widgets and if I position the hidden div in the bottom of the page then it never gets updated by the first callback.

@app_mts.callback(
dash.dependencies.Output('dispatch-div', 'children'),
[dash.dependencies.Input('load-data', 'value')])
def dropdown_selected(value):
if len(value) > 0:
    return value

@app_mts.callback(
dash.dependencies.Output('table', 'rows'),
[dash.dependencies.Input('dispatch-div', 'children')])
def update_table(data):
     print data