I have had this issue since April. At the time my Apple warranty was still in effect. I have worked on the problem off and on for 6 months because, frankly, I'm a turn it on use it type of gal. I get frustrated with computer issues, so I only work on it periodically.

My MacBook Pro (bought in 2006) looses wireless connection on any network I'm on. I have tried it on three (I have the Airport, BF has Belkin, school/work has whatever a large school district would install in an elementary building). I have OS 10.5.8. On all three networks, all other computers work, which are a variety of Macs and PCs. My computer will hold a connection to the wireless network if it is within 2-3 feet from the router. Any farther, and it looses the connection. Sometimes it will hold the connection for a couple of hours, other times it looses it in the first 5 minutes I'm connected. I know it's not any of the networks because other computers work on them just fine. My computer is the common issue on all the networks. I have spent hours and hours and hours with Apple Support. All my settings on the network are accurate. The problem seemed to start when I upgraded to 10.5.8. So, I went back to 10.5.5 but still had the issue. Then I took off 10.5 completely and reloaded 10.4 but still had the issue so I reloaded all the upgrades. (That took hours to unload check for issues, and reload). In the mean time, the Genius say that I have "interference" since the problem could not be duplicated at the Apple Store. However, at the Apple Store, the network signal is extremely strong over the entire store and we could not get more then 2-3 feet away from the source without going outside, which they said they could not do and still use their diagnostic equipment (some of it is hardwired). They did check the airport card and say there is nothing wrong with it. In the middle of all this, my hard drive corrupted. I had it replaced with fingers crossed but still have the connection issue.

I am now thinking of replacing the internal airport card. Do you experts think that would be my next step? Also, where do I get the airport cards, which one do I get, and how hard is it to install? If this does not work, my next step is to buy another airport hub and expand the signal strength. Does that sound like a reasonable idea worth trying?

Thanks for any help,