Sudden Packet Loss Problem

I have a wireless network using a Linksys BEFW11S4 and Alcatell DSL modem.
All has been working fine on my 4 wireless computer home network until 4
days ago when everything slowed and a tracerout showed a large percentage of
lost packets at several network routers. Others using Bellsouth as their
primary DSL ISP have reported the same. Although packet losses do show on
Bellsouth routers, they also appear on routers outside the Bellsouth
network.

Is it possible my linksys wireless router or dsl modem is messing up packets
prior to transmission? Is it possible a Bellsouth router is messing up my
good packet at the very beginning?

Any testing suggestions I could try to find the problem greatly appreciated.