Hello,

I do not have an Apple Extreme card, but can give you some thoughts on it.

Wireless communications happen in the 2.4 GHz range, where a number of other devices transmit and receive, such as a cordless phone, and perhaps wireless remote controls like garage door openers, and maybe pet tracking devices.

A radio signal is an EMF (electro-magnentic field) transmission, so yes, having the magnets out of the way is a good idea. But there are other things to consider too, such as steel, large electric fields like a big electric space heater, thick walls, cement / brick walls, perhaps special flooring. Large monitors nearby can also raise the "noise floor" causing garbled communications. I know, for example, that my garage door opener interferes with one of my ham radio units.

You did not mention if you were in a home environment, or an office. Perhaps you are in a hospital in the X-RAY department with lots of lead in the walls.

Think of your wireless card like a walkie-talkie. You would like a clear-as-possible shot between your computer and the access point.

If you can give us the model number of the unit, we might be able to help you research externnal antenna options.

Christian