Compact Framework SqlClient Classes Don't Actually Inherit From System.Data.Common.Db* Classes?

As you all know, in Framework 2.0 on the desktop platform you have the convenient "abstract" Db* classes that can be used to write more generic code. For instance System.Data.SqlClient.SqlConnection inherits from System.Data.Common.DbConnection, and so forth. Now the docs clearly say that this applies to the corresponding classes in the Compact Framework. And i have seen this implied by other web searchs I've done. However this does not seem to be the case -- or, I'm missing something somewhere.

The following simple code on the desktop platform compiles OK:

using System.Data;
using System.Data.Common;
using System.Data.SqlClient;
DbConnection conn = new SqlConnection();

However it doesn't compile in a compact framework project: "Cannot implicitly convert type 'System.Data.SqlClient.SqlConnection' to 'System.Data.Common.DbConnection'".

Reflector also indicates that the Compact Framework class doesn't inherit from DbConnection.

OK, so am I missing something here, or what was the reason that Microsoft did it differently??