I read with interest this account of extremely aggressive bees.  I
personally have never encountered anything like this in my 25 or so
years with the bees, and am amazed that a hive would be this
aggressive.  I assumed at first that Scott purchased a new package, but
on rereading his post he really doesn't say where his original colony
came from.  I am quite surprised that smoke didn't have a calming
effect.  I wonder if many of you have read Kim Flottum's column in this
month's Bee Culture magazine.  In it he describes his experience in
working with an AHB colony in Texas.  He reports exactly the sort of
bees that Scott has, although he took more precautions to guard against
stings.  Dave Eyre also posted to this thread on the risk of getting AHB
stock from breeders.
 
Incidentally, on the related topic of introducing and removing Apistan
strips, this is what I do to make my entry to the hive as non-intrusive
as possible:  I put the strips in the lower of two hive bodies or the
middle of three.  I crack the hive bodies without removing the cover or
inner cover, blow in a short puff of smoke, then tip the upper hive body
up from behind (pull it back an inch or so to keep it from sliding
forward off the stack), and while balancing the upper HB with one hand I
slip the prefolded Apistan strips in place or remove them with the other
hand, then with another puff of smoke to send bees back between the
frames, I gently lower the HB back into place.  It takes about a minute
(maximum) per hive, with very minimal disruption. (However, I doubt if
even this would have worked for Scott's hive.)