Originally Posted by madmachinist
make sure that the icon is not hidden, in a folder or hidden in a folder. to check if the icon is hidden, press the menu key and check off "show all". this should make any icon that is has been hidden in the main menu or in a folder show up as a transparent version of the normal icon. if you find a transparent version of the sms/mms icon, just highlight it, press the menu key, and uncheck "hide".
The issue is not a missing/hidden icon... it's that the SMS/MMS messages do not show up on the MESSAGES list section of a TODAY screen.