lunixhacker is right in my case, too. X201 with an Ultimate-N 6300. Running Kernel 3.2.0-22 (64-bit)/12.04(Beta2). Same symptoms, on boot wireless works for a few moments, then goes down to 1Mb/s until, ultimately, the connection drops and re-connects into the same cycle. Workaround from #164 does not work with this build. Again, issue only occurs with UNencrypted connections. WPA/WPA2 n-connections work fine.