Inspector Activate Problem

In my appointment ribbon I have the following code that adds an event
handler to listen for inspector activate events.

private void AppointmentRibbon_Load(object sender, RibbonUIEventArgs)
{
m_inspector = (Outlook.Inspector)Context;
((Outlook.InspectorEvents_10_Event)m_inspector).Activate += new
Microsoft.Office.Interop.Outlook.InspectorEvents_10_ActivateEventHandler(AppointmentRibbonInspector_Activate);

}

The problem is that on some machines it appears that the Inspector
Activate...

Inspector Activate Problem