Thanks for the info on Dropbox, I realise I was lazy to ask and am getting a bit too much out of touch with computers/IT/internet considering how much I used to be involved with them.
How it should work - Unless the switch lights up the ECU might not talk to the laptop anyway, but if the switch has been lit in the last several minutes it will, or if it has just had main power feeds connected it will. But unless there is 12v on the red/white, while you might be able to connect you won't see any readings such as temperatures/pressures etc.
As memory serves, at least in case of OMVL (and would imagine the same will apply to other AEB systems) there were mostly little changes between most 4.X software, except for pre and post v4.7, where 4.7 was necessary to connect to later versions of one of the suffixes. I'm sure a chat with a tech support guy/ex tech support guy such as Tinleytech/Dai Brace (classicswede on Lpgforum) would clear up what version should work with what suffix, because they will have been used to answering many questions on this specific point.. memory should serve them better on it..
Still, will be surprised if you can't connect using a version of software you already have.
Simon