Thank you Keith, I try reset it. May be anybody else see that bug? How about new ZDs.
New iPad and iPhone 4s, 5 also Android and notebooks - don't have any problems and works fine (rate limits too), my first problem came, when man with iPad2 come to me and showed problem with Internet sites. Of course may be it's Apple problem, but Google search help to me found info about 802.11d with Ruckus wi-fi and it's really resolve problem.
Before return back iPad 2 I checked internet speed (speedtest.net), and see... 30Mbit/s... wow. I uncheck 802.11d box, reconnect to wi-fi and see again - 5Mbit/s.