Using LR 6.5 VuGen and recording through IE5

I'm recording an action featuring html radio calling Javascript. Here's the situation :

- 2 frames
- 1st one with 5 radio boxes
- 2nd one with a submit image.

My actions :

* Choose a radio box in the 1st frame
-> A Javascript (launched with a onClick event) updates severals 2nd frame hidden values.

* Post the form in the 2nd frame using a submit button.
-> A Javascript (launched with a OnSubmit event) checks if the user chose a radio box (error message with a popup if not)

When I replay this script, I got this error message that means I have not choosen a radio box... In fact, I think LR did not record my radio choice...

Any idea to force LR replaying my script choosing a radio box ?