I have a theory on Avi's problem, and that's that the server is hosted here in the USA, and given the location of PSW's offices, probably in MA. Because of this, you have to hop across a few different continents to get to the server. There are only a few connections across the atlantic and pacific, and I would be willing to bet you're having issues at times of high international traffic load… namely the World Cup this time of year. So, 10 dollars says that when the world cup games are on, you have more issues. If you want to test it, and you can prove the hypothesis wrong, I'll mail it to you. It's just a guess anyway.
I also have a theory that my issue is with my laptop, since I've been finding similar issues across other websites and it seems to be solved after a reset of my wireless card and remains consistent for a week to two weeks.