I've never been so baffled by a Mac behavior. Wondering if someone can help. Just purchased two weeks ago a "new" refurb iBook from Apple's site, a 14" 1.3Ghz with a gig of new RAM. The problem: I can't get it to connect wirelessly with our well-established wireless broadband home office. Some helpful details: *** This iBook connects just fine when plugged into an Ethernet cable. *** This iBook has connected wirelessly, but only for about a minute or two at a time, and then I get the following error message: *** We have Comcast cable at our home office, and use a Linksys wireless G WRT54G. *** We have 2 other iBooks and 1 PowerBook, all connect wirelessly just fine. They're each using DHCP, but I can also assign a fixed IP address, and they work fine with those as well. (I also have a G5 2G, but that's Ethernetted in). All of my Macs have in excess of 1 gig of original RAM, and are all running the most current software updates and 10.4.3. *** I've used Macs extensively since 1991, and know a fair bit about them. *** This iBook has had Onyx run a few times on it (in attempts to fix the problem). I've repaired permissions over a dozen times. I've also trashed the following .plist files: com.apple.internetconfig.plist com.apple.internetconfigpriv.plist com.apple.internetconnect.plist com.apple.internetpref.plist com.apple.recentitems.plist *** In this iBook's Network settings, I've tried using DHCP, and the numbers come up identical (with a diff IP address of course) to the other Macs that are connecting wirelessly just fine. *** The airport card strength (in the right side menu) shows full bars all throughout our home office and house. It's fully lit up. *** Running Network diagnostics often says "It looks like you are connected to the Internet" but I'm not. *** I've tried shutting down all the other Macs, to see if they're somehow part of the problem. *** I've tried setting the IP address manually (over 30 times, with a variety of IP numbers). *** I opened the keyboard and removed and reseated the Airport Extreme card. Same with the RAM: removed and reseated it. I've restarted the Mac, the router, the modem, honest-to-god even my entire house electrical circuits 'till the cows come home. *** When I take the iBook to other locations (local cyber cafes, even the Denver Apple store) it lights up like a Christmas tree, and I'm able to wirelessly get on in a heartbeat. *** When friends stop by (on both Mac and Windows laptops, THEIR computers hook up wirelessly immediately. As I said, I've never been so baffled. I think: if it was hardware, it wouldn't work at the other locations. If it was the router, or its settings, the other 4 Macs wouldn't connect. Any ideas? I will never be so grateful for a fix!!