I think it's a bug in the Dispose() method of ShapeCollection. If I look at this method using for example .NET Reflector, with Microsoft.VisualBasic.PowerPacks.Vs, Version=9.0.0.0, it says this:

    foreach (Shape shape in this.m_Shapes)
    {
        shape.Dispose();
    }

And if I look at this method using Microsoft.VisualBasic.PowerPacks.Vs, Version=10.0.0.0, it says this:

    for (int i = this.m_Shapes.Count - 1; i >= 0; i--)
    {
        this.m_Shapes[i].Dispose();
    }

Clearly, the implementation has evolved between versions. The latter one doesn't rely on an Enumerator object and therefore cannot fail with the error you show.

What's strange though is your stackframe seems to imply you're running off version 10, which shouldn't use the enumerator?? Maybe you need a VS 2010 update? Or you can also check at the Dispose implementation on the Microsoft.VisualBasic.PowerPacks.Vs you're using.

EDIT: after some digging, your application indeed runs on an old version of the VB Powerpacks. Upgrade to VS2010, SP1 or copy the DLL from a good installation. For this specific Dispose bug, you need at least 10.0.30319.1.