Intermittent Wireless Connection, Dropping Wireless Connection

Question

I am asking this in hopes of finding at least some way to diagnose my problem and hopefully eventually solving it. My wireless connection currently drops at varying amounts of time. Sometimes I can go 20mins others merely 5mins. The Airport reads that I am still connected and have a strong connection but when I try to navigate to a page with the browser (either firefox or safari) it merely times out after trying to load the page for up to a few minutes. I have changed the channel and frequency of my router (first router I tried was a Trendnet TEW-432BRP) and I have no cordless phones or other possible wireless obstructions. (I do have a very very infrequently used microwave but being that it's on the other side of the house and I can be sitting next to the router I doubt this is the culprit)
Then I tried changing routers to a Belkin N1 Vision router. Same issues. Additionaly worth noting all other PC's and linux machines on my network (about 4-5 other computers) all work just fine with out dropping their connections (with both routers).
Then I brought my original machine (a white macbook less than a year old) into the apple store, thinking at this point it was a hardware problem with my machine. They the replaced the airport card twice and the logicboard once. Eventually decideing that they should just replace the whole machine. Now with my new unibody I thought I had finally illeviated the problem but now I am having the same issues with an intermittent connection again.
If I turn off the Airport card and turn it back on again usually it will reconnect and allow me to browse again. But not always. The odd part is that generally when using another program that accesses the net the connection does not seem to be interrupted (such as with bit torrent). Very odd.
Anyway I tried using my computer at a friends house with the same trendnet router (his router but same model) and still the connection issues persist. Any ideas on what I can do or try to at least even begin to understand why this is happening would be helpful. I want very much to get to the bottom of this. Thanks for your help.

Answer 1

You didn't get the Apple Store to replace a white MacBook with a unibody?!
Anyhow - the connection problems could easily relate to an incompatibility between OS X and the router in question. Or it could simply be a setting on the router that isn't working well. To assist in the diagnosis... can you please supply:
1) The security mode of the router? (WEP or WPA/WPA2 and AES or TKIP).
2) The network mode (G/N)?
3) The signal strength as reported by Airport (RSSI)
You can get most of this information (all except the security mode) by holding the option key down whilst clicking on the Airport icon in Finder. For the security setting you can go to your routers configuration screen (or you can get it from the command line).
Cheers,
Rodney