Qgis 2.6 and 2.8. Custom form and Init function

Newbye with Qgis, i try to apply the good tutorial written by Nathan "Custom feature forms with Python logic". I try his sample on qgis 2.6 and 2.8.

I altered the sample to allow field initialization by setting default values.

The main issue is when the user click on Ok button, the validate the form is accepted anyway (the dialog.accept function is not run).

I read the bug report http://ift.tt/1GjMGME which relates the same problem.

The second issue is that the init function is launch when the user wants to show tha attributes table. i get an error on the feature object. Obviously the logic is not the same !!

The python logic as explained by nathan is what i need.

As newbye i may mistaken with code, so is this logic working for others users ?

Otherwise, Are there any workarounds available at this time ?

Thanks in advance.

Regards

Xavier