It was un-clear from the message wether they did it just to my personal account or as part of a larger group of users, I would still suggest contacting them if the problem exists today.
As far as why do sites continually upgrade???
Simply because the technology changes so often as new releases are implemented. With the scope of the internet - it is impossible to really know how a planned upgrade will affect EVERY part of a dynamic website like PB. Why does IE & Firefox and everything else upgrade.... simpley because they have to , to keep up with technology as well as hackers!!!