Help Need help with my Mytouch 4g LED/ wont flash when receiving sms

[lollikeduhh]

Hello, so out of no where whenever i get a sms, i used to have my LED light on the top left flash green and a notification on my notification bar. but recently it just stoped? i get the message preview in my lock screen and then it goes away. Can anyone shed some light in this situation?

 

[landovr]

Have you tried restarting the phone or doing a battery pull.