Augie, here's still one more thing to consider regarding your Pacbell DSL problem if you are using WindowsXP. This is an SBC link re Windows XP Drivers and FAQs.
OT - Augi - I found Norton SystemWorks doing crazy things as well. Every time I turned the computer on, the Norton scan would find corrupted files which it prompted to fix........I later found out that, more often than not, it was Norton itself that was corrupting the files then fixing them. Took it off my system have had no problem since.