I have added a new Data Deployment package in my DDT project and I get a few exceptions:

1. When deploying a uniqueidentifier column that contains NULL values, I get an Invalid Cast exception. After filling up all values it works fine.

2. When deploying a nvarchar column that contains NULL values, I get an exception saying that it cannot convert DBNull to String. After filling the values here too, it works fine.

3. When deploying a timestamp column, I get an SQL exception saying that timestamp columns cannot be assigned. Which is true, since timestamps get values on their own.

I can provide you with the package if you think it could help more.