As you have used A-B you need to use the Invert option in the decoder setup, alternatively create the maths channel as CanHigh - CanLow which would be B-A
You will need to change the Baud Rate to 250kbaud as shown here
If you look at the dates of the posts they are old so you are unlikely to get a response, as the poelp may no longer be acitve on the forums. I would suggest you post your issue, and what information you have gathered to date in a new topic to see if anyone can assist.