help! m8 will only call last number dialed!

no matter where i call if its through ther phonebook or thorugh direct dialing, it just goes back to calling last number dialed. so if i called home using my phonebook and after talking hung uo, a few minutes later i want to call a friend lets say uri it dials home again! if i go to keypad and dial my friend by inputing numbers does the same! no matter what i do it goes back to calling home, unless i restart the phone! and i have restarted it 3 times so it wasnt a 1 time deal. anyone had this before?! anythign i can do? pleasel et me know!!!