I've just had a look through my account and mine is showing as "authorised" as well. auctionWorks aren't necessasrily anything to be worried about though. They are used by some sellers on e-bay to handle checkout facilities ( click here ). It may well be that the first time we won an auction where the seller used this tool, then we clicked a box authorising this without realising it. It would just mean that eBay and auctionWorks could send & receive data about you as you have authorised it.
the best way to find out would be to turn the "feature" off (as you have) and keep your eyes open the next time you win something on eBay. If the seller is using auctionWorks, have a very thorough read of any screens you are asked to accept.
It might also be worthwhile e-mailing eBay on their policy for this kind of thing - I've had a quick sniff on the internet and it seems that it is normal for ebay to activate these kind of things as part of upgrade programs...
Good luck and let us know if you find anything out!