MacBook Air + Time Capsule frequently dropping internet connection

Question

I too have been having frequently dropped wireless connections between my MacBook Air (MBA) and my Time Capsule(TC). My TC is connected to a cable modem and I also have an Airport Extreme Base Station (AEBS) at a different part of my house which is used to extend my network connecting via ethernet to a PC running VISTA, and wirelessly to a printer and an older MacBook. I also connect wirelessly to my home network with two iPhones, a Squeezebox 3 with a server running on the PC. I have an Apple TV and a Squeezebox 2 connected to my TC via ethernet.
When my connection drops I will either see a Time Capsule disconnect message or if I am surfing the web, the browser just hangs. The wireless ICON strength is still pegged a the max level. None of my other devices (wireless or ethernet) connected to the TC or the other AEBS seem to drop their internet connections. I can re-establish the connection on my MBA by either turning off my MBA's Airport wireless and then turning it back on or by running the network diagnostics. The latter method usually shows green lights for all but the "Internet" and the "Server" which will have yellow lights. Usually when I select my wireless network and press continue, it will prompt for my WPA2 password which I have to reenter even though I always check the box for it to remember the password in the keychain.
After reading the various discussions on disconnect problems and trying the various "solutions" I was still having the disconnect problem.
Last night, I decided to turn off my Time Capsule and was then able to maintain an internet connection for considerably longer than before. Perhaps it was one of the other "solutions" that caused that. After turning my TC back on, the disconnect problem reoccurred within about 5 minutes.
Next, I did my too frequent Time Capsule remedy which was to disconnect the power and then reconnect the power. (Seems like some of these devices (APPLE TV included) could use power switches.) I then deleted the .sparsebundle backup file on the Time Capsule. I was then able to restart Time Capsule backup and things have been running uninterrupted for over 12 hours...still backing up (20GB in 12 hours? Doesn't seem very fast!). I can report back later if this actually "fixes" my disconnect problems in the future. I am dubious that it will.
I have several questions about the MBA and the TC/Time Machine backup operation.
1.) I often forget about the TC when I close the lid on my MBA and haul it off to work. At work (connecting via ethernet), I will eventually get a TC disconnect error. But I am wondering if there are points in the backup process where a random disconnect will cause some sort of TC corruption. What is the recommended way of handling this? Should I always stop the Time Machine backup before turning off my MBA? (A nuisance if so!)
2.) What is happening when the TC backup operation stops functioning and hangs up the MBA's internet connection? (I see lots of messages logged in the system log when this happens; but, of course, I don't have much of a clue of which ones are normal and which are not normal. I could send a copy of the logs when it happens next (I am assuming it will).
Also one other anecdote. A few months back, I had taken another AEBS to my work to use during a training conference. My MBA kept dropping its connection while the other PC laptops in the room maintained their connections...(very embarrassing!). Maybe one of the other "solutions" would have fixed the problem or maybe if I had just turned off my Time Machine backup it would not have disconnected. I will repeat that exercise when I get a chance now that I have some things to try.
It seems pretty clear to me from my own experiences and the discussion reports of others that the disconnect problem lies in the MBA's wireless internet connection software or the configuration of it. It seems like it is having difficulty recovering from various wireless connection "mishaps".

Answer 1

Folks, I was having a very similar problem for the last 6 months. My connection was fine until June 2008, after which my Macbook and my Time Capsule would constantly conflict. If I rebooted or reset the TC, or the MB, things would be fine for a few minutes or sometimes a few hours and the problem would recur soon thereafter. About a month ago, I had to do a clean reinstall and the problem vanished for about 5 days, after which it reappeared. My MB never had a problem at work, or at someone else's home or with other routers, only with TC. Apple sent me a new TC, then they replaced my Airport card but the situation did not change ... UNTIL ABOUT AN HOUR AGO.
An hour ago, I called Apple for the nth time in the last 6 months, and the rep heard me out (just like the previous n-1 reps). He then asked me to to System Preferences --> Accounts --> Login Items and asked if Real Player Downloader showed up in my list. Indeed it did. He asked me to remove it, and told me that Apple had just figured out that the Real Player downloader was recently found to be causing a drop in the connection between Macbooks and the TC (as well Airport Express).
The problem I've been having baffled everyone. All the previous reps, the guys at the Genius Bars, nobody had a clue. Joe (the rep I spoke with this morning) seemed very confident that the removal of the Real Player Downloader from the list of login items would resolve the problem. So far, so good. My connection seems solid (its only been an hour, but earlier it would drop after 5 minutes of use).
I hope my problem that (literally!) used up hundreds of hours of my time has been finally resolved. I hope this solution will work for at least some of you as well. What gives me hope is that this solution is logically consistent with the history of my problems. I probably first downloaded Real Player in June 2008. And when I did a clean install, I remember downloading Real Player a few days after the reinstall. So I'm pretty hopeful that my issue has been finally resolved.
Shame on Real Player for putting out a defective piece of software. And thank you Joe!