Why can't i put any widgets on my android home screen?

I have a samsung gem (SCH-i100) and the problem is that i can't add any widgets. Before, I was able to add them but, i don't know what happened after. All the shortcuts, folders, and wallpapers work fine, but the widgets aren't working. every time i try to "add" widgets a box comes up and says, "Sorry! The application Settings (process com.android. settings) has stopped unexpectedly. Please try again. Force close". Any suggestions to fix the problem or should i just go to my carrier?