POP woes with Yahoo Mail

I'm pretty happy with Yahoo Mail, having been a customer since the service first started, however, I'm having some problems now that I've started using POP access.

Throughout the day, I get prompted by Mail on Mac OS X to reenter the password for my two POP accounts (one for my "@yahoo.com" email address and one for my "@matthewadams.org" address). This happens probably 10 or more times per day. It also happened when I was using Microsoft Outlook 2007 on Windows XP. Oh, and yes, I am checking the "remember my password" checkbox.

Naturally, I contacted Yahoo Business Mail tech support with low expectations of their ability to diagnose and correct the problem, assuming that if I see it from both Mac OS X and Windows, chances are the problem's on their end. Needless to say, my low expectations were met and not exceeded.

Several times each day, I have to reenter my POP password, and it's getting annoying. Anyone else seeing these problems?