Thanks for helping me out by the way.
I've created a short 10-minute screencast that shows how I proceed to create a forward-mapping project. Everything goes well for a while, but in my last attempt, I was able to set my subclasses as "Vertical" mapping, and this time I can't.
You'll also see that I can't generate a database from my model because it continually asks me to "Rebuild" the application.
I've read a lot of documentation on OA and reverse-mapping isn't a problem, but I thought I'd give forward-mapping a try and haven't had much luck. Do you know if there are any good screencasts on forward-mapping with inheritance?
One of the things I don't like is how OA generates the tables. It adds weird tables (voa-keygen) and weird columns into the tables.
Anyway, I hope you can see some of the issues I'm going through with forward-mapping. I'm sure it works, but I haven't gotten it to work for me yet.
BTW, I can't show you my last attempt since I deleted the VS project and database.