I have the same symptoms with this hardware. It might be an upstream probelm of kernel 2.6.35 as I encountered the same behaviour on Arch Linux after the kernel was upgraded from 2.6.34->2.6.35.
Thus, I don't think this is an network-manager issue. Probably this bug is a duplicate of #591707 (https://bugs.launchpad.net/ubuntu/+source/linux/+bug/591707).
I have the same symptoms with this hardware. It might be an upstream probelm of kernel 2.6.35 as I encountered the same behaviour on Arch Linux after the kernel was upgraded from 2.6.34->2.6.35.
Thus, I don't think this is an network-manager issue. Probably this bug is a duplicate of #591707 (https:/ /bugs.launchpad .net/ubuntu/ +source/ linux/+ bug/591707).