yeah, here's my opinion:
alot of people get this problem, and i think that alot of firewalls can block some parts of websites causing the whole website to not function. I dsisabled my Norton and now everything is fine, and faster...
I'm using the free Comodo Firewall Pro and Comodo AntiVirus which i would recommend.
really i don't see what else the problem could be - i'm guessing SeaMonkey connects to the internet differently to IE and Firefox.
but heres a few things i did:
1) get this
http://www.dslreports.com/front/DRTCP021.zip
then run it and at the bottom select what you use to connect to the internet from the dropdown box and in the small box to the right of it type 1492, click save and exit. reboot your computer.
2) in firefox, type about
:config into the address bar. it will warn you to be careful but don't worry, just don't do anything stupid

at the top type into the filter box 'IPV6' (without quotes) and double click on what comes up (sets it to true). restart firefox.
3) disable firewall (i recommend using Comodo instead)
don't know what else u could do but let me know if this works
gd luck
