Problem calling VB6 forms from .NET app

[Job Lot]

I have a VB6 application which I want to use in .NET application. I have
created a public class in VB6 app which has following public method on it and
compiled my VB6 app as ActiveX.exe

Public Function GetFormFrameHwnd() As Long
Dim frm As New frmCompany
GetFormFrameHwnd = frm.Frame2.hWnd

End Function

The above method returns window handle for frmCompany.Frame2 which is
displayed in .NET Widnows Form using SetParent API call as follows

private void Form1_Load(object sender, EventArgs e)
{
Project1.Class1Class obj = new Project1.Class1Class();
SetParent(new IntPtr(obj.GetFrameHandle()), this.Handle);
}

I am facing two problems here. When .NET application is closed the VB6 keeps
running in the back ground and doesn’t get destroyed (i can see it in Task
List). Secondly controls doesn’t get populated with data and neither of the
buttons work.

Could please suggest what I am doing wrong. Is there any other better way of
calling VB6 forms from .NET app.

Thanks