why is my bluetooth so slow to detect other devices ?

IVE RECENTLY TRIED TO IMPORT OLD RINGTONES FROM MY OLD SONY ERICSSON TO MY IPHONE 4 THE OLD PHONE IS WORKING CORRECTLY SO IS THE IPHONE 4 ITS JUST THE BLUETOOTH SEARCHING DEVICES IS TAKING TO LONG TO SEARCH YET THE PHONES ARE NEXT TO EACH OTHER WHY IS THAT HAPPENING ?