It's been years since I read the old PA comics, but today felt like a good time to relive my experiences by going back to the beginning and visiting PA's origins.
However I've noticed that the entire beginning of the website is perforated in either missing comics, or incorrect URLs.
If you click "First", then you'll get the first strip no problem. Clicking "Next" twice will reward you with "No Comic/Newspost for this issue" for each click. Then you'll get the John Romero/Hotdog comic. Then another two "No Comic/Newspost for this issue"
In fact http://www.penny-arcade.com/comic/1998/12/25/ until http://www.penny-arcade.com/comic/1999/1/4/ all contain the same message until the Myth III explosion. This continues for a long time. I didn't check to see where it stops, though it did seem to become less frequent.
I just mention this, because anyone new to this strip might find it a little disconcerting to encounter such a consistent error message.