Yes..it tends to happen quite often and interestingly..at times, a part of the page comes up..and the other half says that "Internet Page cannot be displayed"...usually closing & re-opening IE fixes that.
I'd like to second the mention from niek_e. I've had it happen four times on me in the past ten minutes; each time, backing out and clicking the same thing got me the page I wanted.
First time occured during an attempt to give a reputation comment to Jwenting in the Geek's Lounge, in the current 'Influential Game' topic. It didn't appear as though the reputation link was working, so I attempted to open in a new page, which came out looking as described.
Second time was an attempt to hit the Software Development bar (forum2) in the menubar above; same effect.
Third time was an attempt to do a search in the Delphi and Pascal forum.
Fourth time was a repeat of the second; I hadn't seen if the actual page were visible under the others (backed out too quickly) and went back to do so. It took three backout/reload tries to correct this time around.
I also saw a small picture of the words 'All the best, Dani' just above the last line of code on that last attempt. I'm not seeing the image anywhere on the page now that it's been reloaded, although I haven't checked the page source for them yet.
We have a php file on the web server which essentially loads a giant array of all of our most common elements ... a listing of our forums, the permissions that each usergroup has (mod, supermod, etc), and a bunch of other such things. This way all of these common elements can be fetched without having to touch the database server.
*All* of the errors you mentioned are related to things that are in this file. However, I can't understand why suddenly everyone would experience the same problem of this one file not loading. Also, I'm not able to reproduce this myself.
It appears that there was some sort of one-time glitch when PHP was writing to this file where either the file was corrupt or wasn't written to entirely or something. Therefore, everyone was having this problem all at the same time. The next time something changed and the file needed to be rewritten, things went back to normal. This is all an automatic process since the file gets rewritten every so often with updated forum statistics and such.
Unfortunately, I was away from my computer when this happened. Had I been here, it would have been possible for me to delete the file and force it to rewrite it on the spot instead of it waiting until its next update, but oh well.
Hmm ... so it WASN'T happening to everyone at the same time? I am talking to jbennet via IM right now and he's saying that he had the same problem on all of his computers for about a half hour straight.
Ancient, is it possible you caught the very tail end of it?