In a grid that I'm using I have the following declaration:
<EditFormSettings CaptionFormatString="Edit detail : {0}"
CaptionDataField="ID" PopUpSettings-Modal="true" EditFormType="WebUserControl"
UserControlName="editDetail.ascx">
</EditFormSettings>
And it works fine as long there are no postbacks within the edit form.
On that usercontrol is a dropdownlist that has OnSelectedIndexChanged event with postback.
When the UserControl has been refreshed the caption is no longer Edit detail : 5 but Edit detail {0}.
Other parts of the usercontrol retain their values .
Yours
Björn