So I have a 3-month old 20" iMac at work. The last few weeks, it developed a problem. After it's been on a few hours, things slow to a crawl. Apps take forever to launch, the system is unresponsive for extended periods of time, lots of beachballs, etc. I did all the usual stuff, including zeroing out the hard drive and installing a fresh system, repairing permissions, running the Hardware Test, etc. I called AppleCare and they didn't have anything more for me to try (nice to see I at least knew and did all the usual troubleshooting steps before calling), so they told me to bring it into a store for repair. I did that. They kept it over the weekend, told me the RAM failed a test, then realized the RAM needed to be reseated. They did that, it passed all the tests, worked great for them, etc. When I picked it up, the repair guy said that if I have the problem again, it might be a network problem. Well, I'm having the problem again. So my question is, anyone know what they mean by network problem and how to troubleshoot it? I'd like to do what I can before calling Apple or bringing it back to the repair shop. First off, being a network problem makes absolutely no sense. I've got an AEBS with about 5 other computers using it. No one else has this problem. Any suggestions?