Hi,
I just upgraded a solution from 8.2.3.4 to 8.4.0.10 , but all the DW7-forms disappeared.
In case someone else has this problem, the cause and solution to the problem is this:
I renamed the database for the upgrade solution, and DW7-forms don't like that. (I don't know if this is the case for forms before DW7-forms.)
The field FormSettingConnection @ DMFormSetting , has a reference to the database name, which needs to be changed, in case you change the database name.
http://screencast.com/t/QhJRunEh4Oa