Just to be sure there is no mis-understanding for anyone following along, the EntitySpaces providers do not replace the clients provided by the database vendors. The clients for SQL Server, Access, and Oracle are included with .NET 2.0. The clients for MySQL and VistaDB come from the vendors. We do not ship them.
Using EntitySpaces LoaderMT, EntitySpaces binaries (including all the EntitySpaces providers) will work under medium trust. We cannot guarantee that a particular client or web host is set up to work under medium trust.
The MySQL client (Connector/NET or MySql.Data.dll) needs to be recompiled to support medium trust. There are some pre-compiled binaries available on the internet that have the required change in them. But, that may be only half the battle. The MySQL client uses sockets, and some hosts do not allow this by default. In that case, you will have to work with your Host to allow the recompiled MySQL client to work under medium trust.
If you do not want to change databases, and EntitySpaces makes this relatively painless, as long as you do not have a lot of DB specific stuff in your code, then you'll have to work with your Host and a recompiled MySQL client. If the Host is not responsive, then changing Hosts may be your only choice.
David Neal Parsons
www.entityspaces.net