Well, OE does cause that problem quite often so it was the "Typical" answer,
and as sure as you are not running OE than maybe the same applies to
something else. I don't know peoplepc, did you run any files or install it
from a CD or anything like that? Maybe it's some kind of shared sponsorship
adware or just adware that got installed while you were using peoplepc's
connection?
Aha, I just discovered their privacy policy and I'm not now so sure that
peoplepc are as "Clean" as they would like us to believe. Look at this page
and check out such things as web beacons and their list of "Partners".
http://www.peoplepc.com/online/legals.asp?locid=1&pageid=1#webbeacons
I'd say you read this whole page and consider uninstalling their "Software".
Make a note of a good phone number you regularly use and your account
details and see if you can dial in and sign in without using their software.
Software should not be necessary for a clean dial in system, just a phone
number and a network name and password because Windows takes care of the
rest. Of course this may breach their user agreement, which is unfortunate,
but for the purposes of testing I think it's legitimate experimentation and
if you discover the problem goes away then you pretty much know they are
pulling a fast one hidden in the small print somewhere, if not they why
would they have a problem with it

.
Charlie