The repair option re-runs the install using the same optios that you specified when you first installed, so unless you chose to install the sample database when you first installed 1.5, you cannot just repair and have it reinstall the sample. There are two options to install the sample. 1) Uninstall and reinstall SF, in which you might want to backup your StrataFrame database so you won't have to worry about losing your settings.
2) (better) open up the DDT to any profile you want and choose to deploy the profile to a server. When the deployment dialog pops up, change the path to the c:\program files\common files\microfour\strataframe\strataframesample.pkg file and change the password to "framework" and deploy it to the server where the StrataFrameSample database is installed and it will re-deploy the database.