FlashWindowEx (window buttons that flash in the taskbar instead of stealing the focus) is not supported in the versions of user32.dll that ships with Windows 95 and NT4.0, so the answer is there's not a lot you can do about it.
Edit: To clarify there's nothing you can do. ypager.exe is calling FlashWindowEx() which is a function that is not defined in the version of user32.dll that ships with WINNT4.0. This is a problem for the developer (Yahoo or whoever develops their software) to fix, but they're probably not interested in supporting Win95/NT.