-        case wxCHK_CHECKED:      flags |= wxCONTROL_CHECKED;
-        case wxCHK_UNDETERMINED: flags |= wxCONTROL_UNDETERMINED;
+        case wxCHK_CHECKED:      flags |= wxCONTROL_CHECKED;      break;
+        case wxCHK_UNDETERMINED: flags |= wxCONTROL_UNDETERMINED; break;
+        default:                 /* do nothing */                 break;