It's FlyerTalk's recent slowdown that's causing the Archives to load slowly (or not at all in some cases). We're experiencing heavy traffic lately, which is impacting our larger forums as well as the Archives (which has 900,000+ posts).
We're hoping to have this problem remedied soon. In the meantime, keep trying the Archives as you may be able to get in on occasion; I just tried it and got in after a little wait. Thanks for your patience...