WaitForCreate returns true when the control is matched and false if it reaches the timeout or iterates through all the controls and does not find a match.

In your case, you need to consider that controls can create before they finish loading. Since code is executed very quickly, as soon as OpenSpan detects that the control is created, it attempts to do a PerformClick. This can be problematic for controls that have JavaScript or Ajax dynamically loading event handlers or actively changing the html. It is most likely that something has not finished loading and it is simply going too fast, causing the action to navigate to fail.