The "bottleneck" doesn't seem to be PHP or MySQL... the PHP page generation times are OK, and the database seems normal. Also, the server load isn't really high.
I guess the server is just getting lots of requests and using lots of bandwidth. Apache or the network connection might be overloaded. Remember that many people are still requesting
http://shoutbox.menthix.net/pid331874.html even though they're not counted as online.
And wj just upgraded some software on this server, so maybe some tweaking is needed again...
Blah. Just go do something useful for a few hours until the site is less busy.
Edit: Right now there are 300 guests online, and pages take about 10 seconds to load, if there are no un-cached images. The individual image requests can really slow down page loading.
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