10.4.11 and "un-openable websites"

Question

Hello
Last night, I updated to Mac OS 10.4.11, via Software Update, on both my PowerBook and my G4. Yesterday, before the update, I didn't have any issues connecting to any websites. After the update, I can open anything I want - except for a site or two. Specifically, the Oklahoma Mesonet site, http://mesonet.ou.edu/, will not open. Safari gives a "server didn't respond" error, while Firefox gives a "The connection has timed out" error. Both are fully up to date.
I tried several things to fix it:
1. Clear Safari's cache and other temp files. No luck.
2. Reboot. No luck.
3. Try Firefox. No luck! This rules out Safari as the problem.
4. Clear prefs for Safari and Firefox. No luck.
5. Call friends in Texas with fully updated G5 (running 10.4.11) - no problems whatsoever. This rules out server downtime.
I figure that this problem is in one of two places: Mac OS 10.4.11 on my Macs, or in the Network at my apartment. I eliminated my Wifi router as the problem, as the wifi hotspot here in the apartment complex isn't any better. I plan on finding a hotspot elsewhere today, to try and eliminate the apartment's network entirely. I can't figure out why the system update would cause the network to have issues with just one site...
One last thought: Could it be a system preferences or network config preferences problem? Where are those stored?
Any ideas?
-Dan

Answer 1

Very informative, thanks.
No luck, however. I typed in the first command you suggested, redirecting the output to those /tmp/ files. It created the files, but then "froze" - and wouldn't give me another command prompt.
I tried "curl --verbose http://mesonet.ou.edu/" and got this:
(computer name here)% curl --verbose http://mesonet.ou.edu/
* About to connect() to mesonet.ou.edu port 80
* Trying 129.15.195.37... * Operation timed out
* Trying 129.15.195.36... * Operation timed out
* couldn't connect to host
* Closing connection #0
curl: (7) couldn't connect to host
This was displayed in the terminal window. THis is also pretty much what Safari says - "the server has stopped responding".
I also noticed that it moved, but http://www.mesonet.org/ won't work either, with the same "server has stopped responding" message. A few other interesting things I've tried/discovered:
Several other sites I've visited show diagrams from the Mesonet site. That is, they link to the image on the Mesonet website so it is displayed on a different page. Unfortunately, the site will load - but the image will not.
The OCS (Oklahoma Climatological Survey - parent group of the Mesonet) has created a standalone program called "Weather Scope" - which pulls data from Mesonet.org and displays it in a much more customizable format. It can't find the data either. It's console log has similar "not found" or "timed out" style errors.
Furthermore, to eliminate the Macs entirely, I tried using the browser on my Nintendo Wii - which couldn't load the site. Wierd. The Wii is currently networked to my WiFi router, so this doesn't rule out the router, but it does rule out the macs. I tried rebooting the router, and it didn't work. I made sure the router was not blocking any websites, etc - it's not - and rebooted it. It still didn't work. Very odd.
I think this may be an issue with the Mesonet server itself - although why my friends in Texas can see it while I can't despite being just a short distance away, is baffling.
Thanks for the help!