Why is the wireless connection between my MacBook and AirPort Express so unstable? The wireless transmit rate of my MacBook Core 2 Duo is extremely unstable. That is, when I connect to my AirPort Express the transfer rate is good for about one minute and after that it suddenly drops (option click on the AirPort icon shows a transmit rate of 1...).

The strange thing is that when I then click on the AirPort icon next to the clock and new networks are being searched, the rate gets normal again for about 10 seconds. Then again all running downloads and page load stop until I click again.

I use the same network with a MacBook Pro without any problems. I've googled this issue, tried to switch wireless channels, switched back to 802.11g mode (it runs on n and g compatible mode normally) but nothing helped so far.

Any ideas what could cause these transfer rate drops?

Update

Not sure if that's of any use but in the AirPort Utility it says Signal -24, Noise -95 and Rate 1 (it raises when I click the AirPort icon).

Update II

One solution seems to be to switch to 802.11n only 5 GHz (2.4 GHz does not help). The downside: iPhone and many older notebooks don't support it...
Something to try is to turn off IPv6 support in your networking preference control panel for wireless, and even for ethernet if you are hardwired.

Mine would drop connections randomly and I'd have to mess around and eventually would pull its power and let it restart to restore sanity. Then, I read somewhere it was a problem with IPv6 support, and turn it off on our Macs. Now it's very stable. 

I stopped using it for my wireless router, and now use it for AirTunes. Very seldom will it lag, and when it does it'll sync up again by itself. I really can't remember the last time it "weirded out" on me, even though some days I'll be playing music through it for most of the day.