have you drank any of your batch fat nub? does it taste sour at all? it seems to me that the presence of calcium lactate may provide the potential for a reaction to occur forming lactic acid, and thus causing a sour taste... just a thought though.
i too just made up a batch not 5 minutes ago and only noticed just as i was mixing the corn sugar w/ the juice that about 3 of my 64 oz bottles contained calcium lactate.. so i am hoping that you didn't get a sour batch, which would then bode well for myself.
i was actually reading a guy's post in the giant apfelwein thread (http://www.homebrewtalk.com/f25/man-i-love-apfelwein-14860/index248.html#post489699
... its the last post on that page) and he complained of sour taste when using apple juice w/ calcium lactate.. so it had me wondering what the deal was.