One thing I noticed with WSOI and SQL Server Express 2008. When creating a new database you enter the name you want to use and when it is created the actual name is prepended with the sites username just like in WHM. The same goes for a database user.
In trying to get WPI to use a database that I created through WSOI I was not able to use the prepended portion of the database user. For example
The web site owner is Owner and I create a user called DBUser then the actual user in the database is Owner_DBUser But when using WPI to install a package I can only get it to work if I use DBUser by itself.

Now, in MS SQL Server Management Studio when I look at the properties of the database user Owner_DBUser the User name and Login name both show the same - Owner_DBUser.
But when I pull up the properties of dbo it shows the Login name only being DBuser.

So is there any inconsistencies here or is this how it should be?

If the user is listed as Owner_DBUser in my list of users should that not be used when WPI creates a database for a applicaiton? Instead I have to use just DBUser.

Also, not a big deal but when saving a new user in the WSOI for MSSQL and assigning to a database it displays a message that MySQL User blah blah was added to the database.....