Package Works In BIDS, But Not In SQL Server 2005

Most of my packages that I've created in BIDS will NOT run in SQL Server 2005. The simplest one that I have fails during a script task that calls external managed code. I've done all the steps outlined in "Referencing Other Assemblies...", but I'm still getting "Object reference not set to an instance of an object." Here's a sample of a script that's having a problem. The line in green is the one that seems to be cause of the error. This is extremely frustrating. This code will even run from a command line console without error. Why is it so difficult to deploy one of these projects with managed code?



Code Snippet

Public Sub Main()
Dim variable1 As String = DirectCast(Dts.Variables("packagevariable1").Value, String)
Dim variable2 As String = DirectCast(Dts.Variables("packagevariable2").Value, String)
Dim variable3 As Integer = DirectCast(Dts.Variables("packagevariable3").Value, Integer)
Dim variable4 As String = DirectCast(Dts.Variables("packagevariable4").Value, String)
Dim filePath As String = DirectCast(Dts.Variables("filePath").Value, String)
Dim variable5 As String = DirectCast(Dts.Variables("packagevariable5").Value, String)
Dim results As Boolean
Dim fileGenerator As IProviderInterface
Dim intFactory As integrationServiceFactory = New ProviderIntegrationServiceFactory()

fileGenerator = intFactory.GetProviderEnrollmentGenerator(variable2, variable5)
results = fileGenerator.GenerateFile(variable3, variable1, filePath, variable2)

If results Then
Dts.TaskResult = Dts.Results.Success
Else
Dts.TaskResult = Dts.Results.Failure
End If

End Sub