cross-thread access error in non-crossing scenario

//Required references:
//  - ActiproSoftware.Shared.Net20 (1.0.93.0)
//  - ActiproSoftware.SyntaxEditor.Net20 (4.0.262.0)
//  - ActiproSoftware.WinUICore.Net20 (1.0.93.0)
//  - System
//  - System.Drawing
//  - System.Windows.Forms

using System;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;
using ActiproSoftware.Drawing;
using ActiproSoftware.SyntaxEditor;

namespace ActiproCrossThreadIssue
{
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            try
            {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);

                //some static GUI element inside Actipro seems to get created on this first thread...
                StaticThreadRunner.RunStaticThread(ActiproIndirectActivator);

                //the second thread fails due to cross-thread access of some GUI element...
                StaticThreadRunner.RunStaticThread(ActiproIndirectActivator);
            }
            catch(Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }

        //STA thread for manipulating our UserControl because it must support drag-n-drop/OLE
        //This thread creates our control, which uses System.Activator to create another control
        //containing the Actipro editor control.
        [STAThread]
        private static void ActiproIndirectActivator()
        {
            IndirectControlHost control = new IndirectControlHost();
         
            //nothing interesting is going on here, just illustrating the cross-thread issue
            control.Focus();
        }   
    }

    //Utility for executing functions on an STA thread
    public class StaticThreadRunner
    {
        //Runs the supplied threadstart as STA thread and always reports thread
        //exceptions
        public static void RunStaticThread(ThreadStart threadMain)
        {
            StaticThreadParameter parameter = new StaticThreadParameter(threadMain);

            Thread thread = new Thread(new ParameterizedThreadStart(ParameterizedStaticThreadMain));
            thread.TrySetApartmentState(ApartmentState.STA);
            thread.Start(parameter);
            thread.Join();

            if (parameter.Failed)
            {
                throw parameter.Exception;
            }
        }

        private static void ParameterizedStaticThreadMain(object obj)
        {
            StaticThreadParameter parameter = (StaticThreadParameter)obj;
            parameter.Execute();
        }

        private class StaticThreadParameter
        {
            private Exception _exception;
            private ThreadStart _threadMain;

            public StaticThreadParameter(ThreadStart threadMain)
            {
                _exception = null;
                _threadMain = threadMain;
            }

            public Exception Exception
            {
                get { return _exception; }
            }

            //ensures thread exceptions get returned gracefully
            public void Execute()
            {
                try
                {
                    _threadMain.Invoke();
                }
                catch (Exception ex)
                {
                    _exception = ex;
                }
            }

            public bool Failed
            {
                get { return _exception != null; }
            }
        }
    }

    //This control is to be used on STA threads and using reflection/System.Activator
    //to create an instance of another control containing the Actipro editor
    public class IndirectControlHost : UserControl
    {
        public IndirectControlHost()
        {
            this.SuspendLayout();
            // 
            // IndirectControlHost
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.Name = "IndirectControlHost";
            this.Size = new System.Drawing.Size(180, 180);
            this.ResumeLayout(false);

            ActiproHostControl myControl = (ActiproHostControl)Activator.CreateInstance(typeof(ActiproHostControl));
            myControl.Dock = DockStyle.Fill;
            this.Controls.Add(myControl);
        }
    }

    //This control is a simple container for the Actipro editor which sets a specific Border
    //on it; which... it would seem... is the point of cross-thread failure.
    public class ActiproHostControl : UserControl
    {
        private ActiproSoftware.SyntaxEditor.SyntaxEditor syntaxEditor1;

        public ActiproHostControl()
        {
            ActiproSoftware.SyntaxEditor.Document document1 = new ActiproSoftware.SyntaxEditor.Document();
            this.syntaxEditor1 = new ActiproSoftware.SyntaxEditor.SyntaxEditor();
            this.SuspendLayout();
            // 
            // syntaxEditor1
            // 
            this.syntaxEditor1.Dock = System.Windows.Forms.DockStyle.Fill;
            this.syntaxEditor1.Document = document1;
            this.syntaxEditor1.Location = new System.Drawing.Point(0, 0);
            this.syntaxEditor1.Name = "syntaxEditor1";
            this.syntaxEditor1.Size = new System.Drawing.Size(150, 150);
            this.syntaxEditor1.TabIndex = 0;
            // 
            // ActiproHostControl
            // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.Controls.Add(this.syntaxEditor1);
            this.Name = "ActiproHostControl";
            this.ResumeLayout(false);

            //turn on drag-n-drop support (OLE / STAThread)
            this.AllowDrop = true;

            //the following line causes the cross-thread exception during Activator.CreateInstance
            ((VisualStudio2005SyntaxEditorRenderer)syntaxEditor1.RendererResolved).Border =
                new SimpleBorder(SimpleBorderStyle.None, SystemColors.Window);
        }
    }
}