DACfx Application - Could Not Load Package From Dacpac

UPDATE: Using Visual Studio 2012 and SSDT 11.1.50512.0

I am using this code to load a dacpac and get the version number from it:

using (DacPackage dacpac = DacPackage.Load(ADacpacFile))
{
retVal = dacpac.Version.ToString();
}

After I install the application on a test machine, this code executes properly and returns the version number on the first run of the application.  I can execute the code multiple times while running and retrieve the version number. 

Once I exit the application and then reload it, the above code fails with the non-descript error message "Could not load package from 'filename.dacpac'.  Stack trace shows:  at Microsoft.SqlServer.Dac.DacPackage.Load(String filename, DacSchemaModelStorageType modelStorageType, FileAccess packageAccess).

I have tried rebooting.  I have tried manually copying over the dacpac files from the install source.  I get the same error every time.  The only thing that works is uninstalling the application and reinstalling it.  Then it works for the first execution and fails again afterwards. 

On my development box, it works every time without error.  Only when I deploy the application via install does this happen.  I have tried two different boxes (both Win7 64bit) with the same result.  The dll's that are being installed with the application are:

Microsoft.Data.Tools.Schema.Sql.dll
Microsoft.Data.Tools.Utilities.dll
Microsoft.SqlServer.Dac.dll
Microsoft.SqlServer.TransactSql.dll
Microsoft.SqlServer.TransactSql.ScriptDom.dll