Firefox 1.3 Mozilla build ID: 20140105004001 DEFECT DESCRIPTION: Can't back to upper level when enter “keyboards”. REPRODUCING PROCEDURES: 1.Enter "Settings->Kerboards->Installed input methods",select any settings 2.Than back to keyboards screen,there is no back button.Press the "X" at the left top, enter "Keyboard settings".User can't back to "Settings" by the back button. EXPECTED BEHAVIOUR: Back to keyboards screen, there should have back button and user should back to Settings normal. ASSOCIATE SPECIFICATION: TEST PLAN REFERENCE: TOOLS AND PLATFORMS USED: USER IMPACT: REPRODUCING RATE: For FT PR, Please list reference mobile's behavior: