Display multiple PDF's in windows forms tab control

I am working on a program that will eventually dynamically create tabs to display pdf files, word documents and text files.  To start I am just using an OpenFileDialog to point to a pdf to create a tab and open the file.  This is working for 1 pdf, with one small issue, I have to click on the PDF control in order for the pdf to display, otherwise its just a grey screen.  My bigger problem is when I try to add a second file to the mix.  When I click the button again to add another file the code executes until it reaches "PDFFile.LoadFile(strFileName);".  At that point I get an error, Exception of type 'System.Windows.Forms.AxHost+InvalidActiveXStateException' was thrown.  I've tried to find a solution but the one I keep seeing is I need to put in CreateControl(), which I am already doing.  Has anyone tried to do anything like this and had success?

            try
            {
                TabPage page = new TabPage();

                tabMain.Controls.Add(page);
                page.Text = strTabName;

                switch (strControlType)
                {
                    case "pdf":
                        AxAcroPDF PDFFile = new AxAcroPDF();                        
                        page.Controls.Add(PDFFile);
                        PDFFile.CreateControl();
                        PDFFile.Dock = DockStyle.Fill;
                        PDFFile.LoadFile(strFileName);
                        break;
                    case "doc":
                    case "docx":
                        break;
                    case "txt":
                        break;
                    default:
                        break;
                }                
            }
            catch(Exception ex)
            {
                var message = ex.Message.ToString();
                MessageBox.Show(message);
            }

Select allOpen in new window