Comment 3 for bug 574709

This problem appears to be related to the kernel. After installing the kernel linux-image-2.6.31-21-generic from karmic-updates, my wireless connection is again rock stable. Of course installing a kernel from an old version of Ubuntu is kind of worrying, but a part from a broken boot splash screen I have seen no ill effects.

Correction to the problem description: It is not impossible to connect to the network, but it requires many retries. After 5-10 minutes of retries, it usually connects, but then disconnects after roughly an hour.

I have previously tried to configure WPA manually, i.e. after uninstalling network-manager. The problem remains. I have also tried to downgrade wpasupplicant to the version from Karmic. The problem remains. But after undoing these experiments, and downgrading the kernel, the wireless connects almost immediately and does not disconnect.