Replicating JavaScript script with VB.NET

I have the following JavaScript script that works as I wish:

var thisPgf = NothingEnum.nothing;

var thisStory = NothingEnum.nothing;

var articleTitle = "";

var contentID = 0;

var filePath = "";

// Open template

var doc = app.open('C:\\Library\\Library Book Template.indt');

// Add articles

var articleList = [56123, 56132, 56138, 56149, 56157, 56168, 56177, 56186, 56194];

for (var i = 0; i < articleList.length; i++) {

    contentID = String(articleList[i]);

    articleTitle = "Article #" + contentID;

    thisStory = doc.pages.lastItem().textFrames.lastItem().parentStory;

    thisStory.insertionPoints.item(-1).contents += articleTitle;

    thisPgf = thisStory.paragraphs.lastItem();

    thisPgf.appliedParagraphStyle = doc.paragraphStyles.item("Heading");

    thisStory.insertionPoints.item(-1).contents += "\r";

    doc.recompose();

    filePath = "C:\\Library\\" + contentID.substr(0, 2) + "\\" + contentID + "\\" + contentID + ".rtf";

    thisStory.insertionPoints.item(-1).place(filePath);

    doc.recompose();

    }

I need to replicate this script in a VB.NET program. Here is how I've done it:

    Dim IdApp As InDesign.Application = CType(Activator.CreateInstance(Type.GetTypeFromProgID("InDesign.Application"), True), InDesign.Application)

    Dim IdDoc As InDesign.Document = IdApp.Open(TemplateFilePath, False)

    For I = 1 To NumArticles

      ContentID = ArticleList(I).ToString

      ArticleTitle = "Article #" & ContentID

      ImportFilePath = "C:\Library\" & Left(ContentID, 2) & "\" & ContentID & "\" & ContentID & ".rtf"

      ThisPage = IdDoc.Pages.LastItem

      ThisFrame = ThisPage.TextFrames.LastItem

      ThisStory = ThisFrame.ParentStory

      ThisStory.InsertionPoints.Item(-1).Contents &= ArticleTitle

      ThisPgf = ThisStory.Paragraphs.LastItem

      ThisPgf.AppliedParagraphStyle = HeadingPgfStyle

      ThisStory.InsertionPoints.Item(-1).contents &= vbCr

      IdDoc.Recompose()

      ThisPage = IdDoc.Pages.LastItem

      ThisFrame = ThisPage.TextFrames.LastItem

      ThisStory = ThisFrame.ParentStory

      ThisStory.InsertionPoints.Item(-1).Place(ImportFilePath)

      IdDoc.Recompose()

    Next I

What is frustrating me is that when I open the INDD file that is saved at the end of my VB.NET program, the text does not automatically flow onto as many pages as are needed. I have Primary Text Frame checked in InDesign. I have Smart Text Reflow checked, and the left and right master pages of the template document have one text frame each, each of which is designated as a primary text frame.

I have tried putting the last Recompose() statement in a loop, not exiting the loop until the Overflows property for the text frame on the last page is false, but nothing makes it flow automatically.

Is there a different way that I should be doing this? Thanks!