Microsoft Web Browser ActiveX returns error WindowActivate Event isn't a valid event name

I use the Microsoft Web Browser ActiveX in a GUI created with GUIDE. In many computers it works good, but there are some in which it returns the WindowActivate event isn't a valid event name error when registering the event. I have investigated a bit and found out, that under the webbrowser control are two diferent objects available, InternetExplorer object and WebBrowser object. They have diferent events: while InternetExplorer has the WindowActivate event, the WebBrowser hasn't it ( http://msdn.microsoft.com/en-us/library/aa752084(v=VS.85).aspx ) In the computer where the error takes place, I think it is because it takes the WebBrowser instead of the InternetExplorer object, but tries to use his events though.

So the question is: how can I force MATLAB to use the InternetExplorer object? Any ideas would be apreciated.

All the computers use Win7 Profesional and MATLAB 2007a. The error comes when running it in MATLAB 2010b too.