Hello everybody,

My PCI Airport Card, recognized as third party by System Profiler (it's a Belkin model, can't tell you the chipset right now), doesn't work when my rig has 4GB of RAM installed. If I pull off just one of the four 1GB stick reverting to 3GB or 2GB, everything is fine.
I'm not an expert at all, so I thought of something related to a 32 bit - 64 bit kernel or driver issue, as in Windows, like: to support 4GB Snow Leopard switch automatically from a 32 bit to 64 bit kernel and the 64 driver for the AirPort card doesn't work. I guess it doesn't make sense, because that's a Windows issue. And actually forcing the 32 bit kernel (checked the "64-bit Kernel and Extensions: Yes/No" description under "Software" section in System Profiler) hasn't solved anything.
By the way, I'm on a Gigabyte P35 motherboard.

Mathieu

This is because in 32bit mode, 4G is the max address space, and your PCI address space is being moved outside. 3G is the max you'll be able to do it in 32bit mode. Whether you can get the card working in 64bit mode depends on if there's a 64bit driver for it as well as if you can do 64bit kernel mode.