I am also facing the same problem.
Have u found any solution?? if so plz share ..
Due to some reason the text input fields used inside the flash presentation are not editable only when the application is running on installed AIR.
When the flash presentation is loaded in Flex it is not allowing the user click inside or edit the text input, to over come this we are setting the focus to text input field when ever the user clicks on it so that the cursor focus is set inside the text input field and user will be able to enter data.
Below is the code change implemented in flash.
function setFoucusToTextInput (e:MouseEvent)
stage.focus = inputText;