UIAutomation - InvokePattern only works while Debugging - Button is not Recognized as a Button

I am manipulating an old program using UIAutomation. The issue I have involves pressing a button usingInvokePattern.

After pressing a button that opens up an explorer window and getting the AutomationElement for the window, I get the AutomationELement for an "Open" button, actually a SplitButton. I can find the element easily, but it comes up as a Pane control rather than a SplitButton Control. However, if I insert a breakpoint before looking for the Button element and manually step through the code in Debug mode, the "Open" button is recognized as a Button.

If I insert a breakpoint after finding the Button Element, the element Name and AutomationID are correct, but ControlType is a Pane instead of a Button. It's bizarre.

The offending code is below: (Net 3.5, VS2010, Win7 x64)

            InvokePattern bPattern = (InvokePattern)button.GetCurrentPattern(InvokePattern.Pattern);
            bPattern.Invoke();

            for (int wait = 0; wait < 50; wait++)
            {
                if (explorerWindow != null)
                    break;

                explorerWindow = reportWindow.FindFirst(TreeScope.Children,
                                                new PropertyCondition(AutomationElement.NameProperty, "Select Report"));

                Thread.Sleep(200);
            }

            explorerOpenButton = explorerWindow.FindFirst(TreeScope.Children,
                                    new PropertyCondition(AutomationElement.NameProperty, "Open"));