My eee PC with Ubuntu 8.0.41 was having problems connecting to a WPA encrypted network and after a bit of research found this: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/210725. This driver seems to work much better. The exact post is this one: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/210725/comments/101, but there may be a better one futher down.
eee pc 901 Wireless driver
18th Oct 2008