title: MFC application crashes on Windows 7
body: <p>I have an MFC application that works on XP and crashes on Windows 7. (I don't have the source - this is a 3rd-party application that the 3rd-party no longer supports; I'm just trying to get the darn thing to run).</p>
  
  <p>Most of the application works, but there is one screen (MDI window) that contains a ton of controls (worst UI ever), including 3 ComboBox controls. Simply moving the mouse over those controls (which are in the contracted state) causes the application to crash with the error "MFC application has stopped working".</p>
  
  <p>From what I can determine using Spy++, the controls are standard ComboBox window classes. They're subclassed of course, and I assume that whatever processing takes place in response to the mouse-over message is causing the fault.</p>
  
  <p>I was kinda hoping that running it in XP compatibility mode would help, but it doesn't.</p>
  
  <p>What sort of thing would cause this to fail on Windows 7 when it worked OK on XP? (Some other parts of the application failed because some DLLs were missing, and I was able to fix that by copying the DLLs from the older environment. I was kinda hoping that this might be something similar).</p>
  
  <p>PS. The old environment had Office 2003, and the new one has Office 2010. While this thing isn't really related to Office, I mention that in case it's relevant somehow.</p>