Help Required - vcds road sign tweak

hi folks i wondered if any one could help. having taken delivery of my nice superb mkiii sportline i decided to look at a few tweaks.

im having a problem with the road traffic signs mod. my hex-v2 vcds fro  ross tech doesnt list the channels as the walk through but i think ive managed the most of it however i have a small problem. when activating the speed notification it seems to be always alarming as if its in a 30mph zone whether or not its recognised a 40, 50, 60 or 70 zone. any one got any ideas how to fix this please?

hope you can assist......