Starting this afternoon I cannot get my yahoo mail thru the yahoo sign in page on my Firefox 3.0 browser only on my IE 8.0

I am using ZA Extreme. Today I did the MS monthly updates but this did not show up until 2-3 hours later.

I am completely at a loss? Any one know what might have happened? WIN xp user

Operating System:Windows XP Home Edition
Software Version:8.0
Product Name:ZoneAlarm Extreme Security