Not necessarily, in fact probably not.
It means you connected to the exchange fine, as your modem/router still had sync/connection to there, but for some reason you could not be logged into your ISP from the exchange. So the problem is between the exchange and your ISP, usually at the ISP end.
Unless you also lost connection to the exchange, in which case the PPP session will usually drop anyway.
My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost.
Internet connection - O2 Standard.