Unable to load native components of SQL Server Compact v3.5

We are updating an application of wince 6 with sql 3.0 to wince7 with sql 3.5 and it gives errors when opening the database. We have tried to execute the example that is in your page “How to use SQL Database in VCSharp” and it gives us the same error.

System.Data.SqlServerCe.SqlCeException was unhandled

Message = “Unable to load the native components of SQL Server Compact corresponding to the ADO.NET provider of version 8080. Install the correct version of SQL Server Compact.” Refer to KB article 974247 for more details. "
HResult = -1
NativeError = -1
Source = “”
at System.Data.SqlServerCe.NativeMethods.LoadValidLibrary (String modulePath, Int32 moduleVersion)
at System.Data.SqlServerCe.NativeMethods.LoadNativeBinaries ()
at System.Data.SqlServerCe.SqlCeConnection…ctor ()
at System.Data.SqlServerCe.SqlCeConnection…ctor (String connectionString)
at sql_demo.Form1…ctor ()
at sql_demo.Program.Main ()

We believe that it is a problem of SQL versions. What version is installed with the .cab that comes in “toradex_sql_compact_v3_5.zip” ?.
Or what version of sql server compact should we install in VS2008?
The version we have now is sql server compact 3.5 SP2.
Thank you

Dear @Tecael,

Thank you for contacting support. I am working on this, please wait for a couple of days, I will get back you.

Dear @Tecael,

Just I would like to confirm with you, Did you deploy spl_demo.sdf and system.data.sqlservice.dll?

We are able to deploy and run Sqldemo application by following step by step instructions describle on the https://developer.toradex.com/knowledge-base/how-to-use-sql-database-in-vcsharp. SQL Server Compact 3.5 SP1 is installed in my PC.

And with the SQL Server Compact 3.5 SP2 version does not work?

Dear @Tecael,

I have installed SQL Server Compact 3.5 SP2 and rebuild the application and tested it on the device it works. Also, I noticed after installing SQL Server compact 3.5 SP2 the files didn’t change on this path : C:\Program Files (x86)\Microsoft SQL Server Compact Edition\v3.5\Devices\wce500\armv4i. It seems only desktop SQL DLLs are updated. Could you please zip the contents on that path and share with us. Let me compare with my PC installed DLLs.