For those who are interested in the database engine used by Power Music: we made the decision last summer to drop Microsoft SQL Server Express 2005 in favour of VistaDB. We needed something that was as powerful as SQL Server express with stored procedures and views, but was straightforward to deploy as a single dll for 32 and 64-bit operating systems.
This decision was based on repeated reports of installation problems relating to SQL Server Express, and we are delighted to say that almost 6 months later there has not been a single report of installation failure of our software relating to VistaDB.

We now use this for all our client-based database software and would recommend it to other developers.

We did become alarmed shortly after making the switch when it was announced that the owners of VistaDB were closing down and would no longer support it. However, not long after that it was acquired by Gibraltar Software who are now committed to developing and supporting VistaDB for the foreseeable future. We are delighted with this as it has proved to be an excellent database engine, easy to configure and deploy, yet with all the client-rich features of SQL. It is used by many companies throughout the world and we will continue to use it for as long as it is supported.