Rooting Xperia Ray (ST18i) with 4.1.B.0587 build

I've been trying to root my xperia ray device by following the instruction given in this post. It doesn't seem to work properly for me. Whenever I try to flash with 4.1.A.0.562 kernel it says that my device USB debugging is off even when I've ticked it. Also I've put it onto MSC mode. When I try to put it on flash mode both kernel.sin & loader.sin is grayed out. Below is the log what I get. 02/016/2014 02:16:42 - INFO - <- This level is successfully initialized 02/016/2014 02:16:42 - INFO - Flashtool Version 0.9.13.0 built on 2013-06-04 22:50:00 02/016/2014 02:16:48 - INFO - Device disconnected 02/016/2014 02:16:50 - INFO - Selected ST18 / 4.1.A.0.562 / Kernel 02/016/2014 02:16:50 - INFO - Preparing files for flashing 02/016/2014 02:16:50 - INFO - Please connect your device into flashmode. 02/017/2014 02:17:28 - INFO - Device connected with USB debugging off 02/017/2014 02:17:28 - INFO - For 2011 devices line, be sure you are not in MTP mode 02/017/2014 02:17:44 - INFO - Device disconnected 02/017/2014 02:17:47 - INFO - Device connected with USB debugging on 02/017/2014 02:17:47 - INFO - Connected device : SonyEricson Xperia Ray 02/017/2014 02:17:48 - INFO - Installed version of busybox : BusyBox v1.18.5 (2011-07-18 07:43:28 PDT) multi-call binary. 02/017/2014 02:17:48 - INFO - Android version : 4.0.4 / kernel version : 2.6.32.9-perf / Build number : 4.1.B.0.587 02/018/2014 02:18:14 - INFO - Device disconnected 02/018/2014 02:18:31 - INFO - Device connected in flash mode 02/018/2014 02:18:31 - INFO - Opening device for R/W 02/018/2014 02:18:31 - INFO - Reading device information 02/018/2014 02:18:32 - INFO - Phone ready for flashmode operations. 02/018/2014 02:18:32 - INFO - Current device : ST18i - CB511VGBZ7 - 1252-6163_R1I - 1248-9545_4.1.A.0.562 - WORLD-i_4.1.B.0.587 02/018/2014 02:18:32 - INFO - Start Flashing 02/018/2014 02:18:32 - INFO - Processing loader.sin 02/018/2014 02:18:32 - INFO - Checking header 02/018/2014 02:18:32 - INFO - Flashing data 02/018/2014 02:18:37 - INFO - Loader : S1_Loader_Root_773f - Version : R4A066 / Boot version : R9A029 / Bootloader status : ROOTABLE 02/018/2014 02:18:37 - INFO - Disabling final data verification check 02/018/2014 02:18:37 - INFO - Processing kernel.sin 02/018/2014 02:18:37 - INFO - Checking header 02/018/2014 02:18:37 - INFO - Flashing data 02/018/2014 02:18:39 - INFO - Ending flash session 02/018/2014 02:18:39 - INFO - Flashing finished. 02/018/2014 02:18:39 - INFO - Please unplug and start your phone 02/018/2014 02:18:39 - INFO - For flashtool, Unknown Sources and Debugging must be checked in phone settings 02/018/2014 02:18:39 - INFO - Device connected in flash mode 02/018/2014 02:18:55 - INFO - Device disconnected And I've attached a sample screen of what I get. Please advise me what to do.. I'm totally lost... even the log says flashing finished, my current kernel build is in 4.1.A.0.587 but not 4.1.A.0.562. Model number: ST18! , Android Version: 4.0.4 , Build number: 4.1.B.0.587