iPray alerts were working fine but suddenly they've stopped working! Please help!

This is most probably because you installed something that's broken your iPhone/iPod Touch installation. Please read below (which applies to iQuran as well)

Important: Some users have informed us that Applications like "Nate True's Dock", Mobile Finder, "Arabic Fix/Support for iPhones" and other applications that change the default behavior of the iPhone interfere with iPray and iQuran! Unfortunately we have no control over other applications and so you must ensure that you have not installed any application that alters the system in an abnormal way as these 3rd party apps seem to interfere with other running apps (especially iQuran/iPray)