my cider smells like vinegar

i tasted my cider this morning after a hydrometer reeding and it has a vinegar smell and a slight vinegar taste.. is this normal will it go away with age? ill try to give all the info i can. i started my cider on 11/8/07 i was in the primary for two weeks and now secondary for one week my hydrometer reeding this morning was 1.012 sg of around 1.080 it has been fermenting at a temp around 57 to 60

recipe:
4 gl cider
3 pounds corn sugar
2 campden tabs 24 hours before pictching
pectic enzyme
sweet mead yeast

after reading more about cider i found most people use brown sugar is the vinegar smell\taste coming from my sugar or em i fermenting to low in temp or is this just a strong cider like more of a apple wine??
if theirs any more info i can give you let me know any help would be rad

cheers fleas ps its not to vinegary to drink so if this is just how my cider is going to be then so be it

firstly, if it smells like vinegar, then it's probably turning into vinegar... do an acid test, and check that... also, keep a close eye on it over the next couple days...

secondly, most people use dextrose (corn sugar) for their cider... there should be no problems there... if you used fresh pressed cider, but only 2 campden tablets, that might be your problem... you want to use one tab per gallon...

temps aren't too low, but at that low a temp, it will take a while to finish... I would recommend an acid test to check for vinegar, and just to keep an eye on it... in a couple months it will either be really good cider, or really good cider vinegar... if the second, then make sure to dump it immediately, and make sure any other batches in the same room haven't been infected... has everything been kept under airlock? vinegar generally only happens if the cider is left open to the air (acetobacteria is airborne, hence the airlocks)...

PS: are you sure it's vinegar-y, and not just sour? green (young) cider can be quite tart & sour before it ages...

yes every thing has been under an air lock the entire time as for it just being green cider this is my first so that might be the culprit.. and how do i do a acid test

thanks for your help

fleas.