I have a lenovo x201 and x200 and that sometimes fails to complete its 4-way handshake with the AP.
when it fails it can take up to 10 minutes to connect. not much of a problem except it is at a school where the class time is 45 minutes which means 20% of the class time is lost just connecting to the network.
Every intel 6200 has this problem but none of the latops with braodcom chipsets have the problem.
we have tried the 13.4 and 13.5.6 drivers same both times. We have tried with HP procurve , Meru and Xirrus Access points.
this is with wpa2 and a 10 character PSK if the PSK is doubled to 20 characters the failure rate goes up and sometimes fails to connect at all.
problem solved. all power management needs to be turned off
under power management on the adaptor and in powermanage ment under control panel there is also an optin for wireless power management as per this article