What I did to back up rogers firmware is use SEUS to update your phone even if it has latest software. After update is successful go to C:\Program Files\Sony Ericsson\Update Service\ db folder there should be 3 files named FILE_XXXXX, (their size is 64kb,9487kb,288381kb you should have something similar).
Copy those 3 files to some folder that is easy for you to find.
Then open latest flashtool go to advanced>decrypt files
when window opens select folder where those files saved.
Select those 3 file and wait for it to finish decrypting.
Once it is done another window will pop up that will assist you to create ftf bundle. Just select all files accept for partition-image.sin and wait for it to finish. Created ftf bundle will be in directory where falashtool was instaled in folder called firmwares.
You are done!
Now you can flash your phone anytime you need to put Rogers firmware back in.
Last edited by zimbashka; 23rd April 2012 at 02:41 AM.