If you dynamically add data to a drop down, you'll lose the dynamic items when you submit the data.
When you submit the data, only the selected value from the drop down is part of the data and not the drop down content. If you want to submit the drop down content, you could save the value in a hidden field and then the value (for that field) would be submitted.
On the second step (user2) you would have to populate the drop down from that hidden field instead when the form initialize.
Jasmin