I was having the same problem with ubuntu 10.04 on a ThinkPad X201 with an Intel 6000 chip. I tried sillyxone's (Comment #20) solution of creating a file /etc/modprobe.d/options.conf
and adding the line
options iwlagn 11n_disable=1 11n_disable50=1
I then removed and then reloaded the module iwlagn. Doing this appears to have fixed my problem, thus avoiding the need to remove Network-Manager and installing WICD.
I was having the same problem with ubuntu 10.04 on a ThinkPad X201 with an Intel 6000 chip. I tried sillyxone's (Comment #20) solution of creating a file
/etc/ modprobe. d/options. conf
and adding the line
options iwlagn 11n_disable=1 11n_disable50=1
I then removed and then reloaded the module iwlagn. Doing this appears to have fixed my problem, thus avoiding the need to remove Network-Manager and installing WICD.
Yippie!