I have an 800 -14 in ibook with Airport with great reception. The Airport extreme base station does not have a modem so it doesnt have an arial extension. I live in a large colonial with the base station on the second floor in the front of the house and the ibook on the first floor in the back. I can walk outside at least 50 feet and still get on the internet and access my laser printer.

I agree with a previous writer that I would check the antenna in the ibook. It could be defective or miss aligned.

I'm sorry I have bad news...Many ibook owners have had the same problem. Here's what's going on:

after much looking through various boards, I've diagnosed the problem as a pinched antenna wire in the hinge...a very common problem (and poor design) on ibooks. Typically, this is what happens: When you move the screen all the way away, it cuts out. Move it a bit back towards you, and it comes back on. The strength of the signal even varies according to how far back the screen is.
Here's a quote from another board: "The problem is in the iBook Hinge... The antennas are located on either side of the screen, and because the airport card is inside the main body of the computer, the cable runs through the hinge (duh...)."

I got off the phone with Apple tech support a short time ago. Estimated cost for repair of pinched antenna wire: $330.00!!!!!

This is a widespread problem. if it hasn't happened to your ibook yet, give it time....

In order to get Apple to publicly acknowledge that this is a design flaw (they are fully aware of the problem). Ibook owners need to barrage them with complaints. You can call apple tech support and lodge a complaint (1-800-275-2273) and/or write them at the following address:

Apple Computer Inc.
Attn: Customer Care
1 Infinite Loop
Cupertino, CA 95014

This needs to reach the same level as the failed logic boards. Please feel free to pass the contact info around as you see fit, however, be nice to apple...

Have you tried lifting off the keyboard and checking the connection between the antenna and the airport extreme card? This topic has come up TONS of times on the official Apple iBook forums, and 99% of the time it was a loose connection. You REALLY have to 'gently force' the connection cap to snap into the airport. I was too gentle doing it, and even though it 'clicked' it was only 1/3 attached. After having a couple days of horrible reception, I checked the boards and saw someone's post about it. Sure enough, I forced the connector harder, and it snapped in 2/3 deeper.

Just a thought. Give it a shot if you already haven't.