I am also having a similar issue. I've googled the problem and it seems that Verizon is having issues with their hardware. I am getting wicked dropped packets atm. For example.. I have the ventrilo window open atm, where it shows the status of the server.... it drops about 30 times a minute. Router diagnostics show a 65% packet loss or higher. Have reset the router to default (which has always fixed similar issues in the past) but shows no positive effect.
Getting slightly irritated. So far, it seems like Yahoo Messenger is the ONLY program that isn't experiencing disconnects or high ping. I see no need to hastily freak out and switch to cable. Seeing as it is a more widespread problem, I'm willing to bet they'll hopefully fix it soon. If not, I'll be calling them up later.