[RoS 5.4 on RB532a]Problem with wireless sessions and cpu

hi,
i’ve got strange behavior with my RouterBoard…
i don’t know how to explain it so here some pics
http://valhalla.urbinek.eu/urbinek/img/mikrotik/2010-06-22_daily.gif
http://valhalla.urbinek.eu/urbinek//img/mikrotik/2011-06-22-175617_1680x1050_scrot.png
and bonus file http://valhalla.urbinek.eu/urbinek//img/mikrotik/supout.rif

why this seassion is still in registration table and why wireless is using so much CPU when it is almost unused?
after turning off and on wireless cards cpu is back to normal

P.S.
[admin@urbiszcze] > /interface wireless export

# jun/22/2011 17:57:09 by RouterOS 5.4
# software id = KG1T-9F6Q
#
/interface wireless security-profiles
set default authentication-types="" eap-methods=passthrough group-ciphers="" \
    group-key-update=5m interim-update=0s management-protection=disabled \
    management-protection-key="" mode=none name=default \
    radius-eap-accounting=no radius-mac-accounting=no \
    radius-mac-authentication=no radius-mac-caching=disabled \
    radius-mac-format=XX:XX:XX:XX:XX:XX radius-mac-mode=as-username \
    static-algo-0=none static-algo-1=none static-algo-2=none static-algo-3=\
    none static-key-0="" static-key-1="" static-key-2="" static-key-3="" \
    static-sta-private-algo=none static-sta-private-key="" \
    static-transmit-key=key-0 supplicant-identity=MikroTik tls-certificate=\
    none tls-mode=no-certificates unicast-ciphers="" wpa-pre-shared-key="" \
    wpa2-pre-shared-key=""
/interface wireless
set 0 adaptive-noise-immunity=none allow-sharedkey=no antenna-gain=0 area="" \
    arp=enabled band=2ghz-b/g/n basic-rates-a/g=6Mbps basic-rates-b=1Mbps \
    bridge-mode=enabled channel-width=20/40mhz-ht-below compression=no \
    country=poland default-ap-tx-limit=0 default-authentication=yes \
    default-client-tx-limit=0 default-forwarding=yes dfs-mode=none \
    disable-running-check=no disabled=no disconnect-timeout=3s distance=\
    indoors frame-lifetime=0 frequency=2432 frequency-mode=manual-txpower \
    frequency-offset=0 hide-ssid=no ht-ampdu-priorities=0,1 ht-amsdu-limit=\
    8192 ht-amsdu-threshold=8192 ht-basic-mcs=\
    mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-6,mcs-7 ht-guard-interval=any \
    ht-rxchains=0,1 ht-supported-mcs="mcs-0,mcs-1,mcs-2,mcs-3,mcs-4,mcs-5,mcs-\
    6,mcs-7,mcs-8,mcs-9,mcs-10,mcs-11,mcs-12,mcs-13,mcs-14,mcs-15" \
    ht-txchains=0,1 hw-fragmentation-threshold=disabled hw-protection-mode=\
    none hw-protection-threshold=0 hw-retries=7 l2mtu=2290 mac-address=\
    00:80:48:6C:88:FE max-station-count=2007 mode=ap-bridge mtu=1500 name=\
    compex noise-floor-threshold=default nv2-cell-radius=30 \
    nv2-noise-floor-offset=default nv2-preshared-key="" nv2-qos=default \
    nv2-queue-count=2 nv2-security=disabled on-fail-retry-time=100ms \
    periodic-calibration=default periodic-calibration-interval=60 \
    preamble-mode=both proprietary-extensions=post-2.9.25 radio-name=\
    urbinek_AP/b/g/n rate-selection=advanced rate-set=default scan-list=\
    default security-profile=default ssid=urbinek_AP/b/g/n \
    station-bridge-clone-mac=00:00:00:00:00:00 supported-rates-a/g=\
    6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps supported-rates-b=\
    1Mbps,2Mbps,5.5Mbps,11Mbps tdma-period-size=2 tx-power-mode=default \
    update-stats-interval=disabled wds-cost-range=50-150 wds-default-bridge=\
    none wds-default-cost=100 wds-ignore-ssid=no wds-mode=disabled \
    wireless-protocol=any wmm-support=disabled
set 1 adaptive-noise-immunity=none allow-sharedkey=no antenna-gain=0 \
    antenna-mode=ant-a area="" arp=enabled band=2ghz-b/g basic-rates-a/g=\
    6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps basic-rates-b=\
    2Mbps,5.5Mbps,11Mbps bridge-mode=enabled burst-time=disabled \
    channel-width=20mhz compression=no country=poland default-ap-tx-limit=0 \
    default-authentication=yes default-client-tx-limit=0 default-forwarding=\
    yes dfs-mode=none disable-running-check=no disabled=no \
    disconnect-timeout=3s distance=dynamic frame-lifetime=0 frequency=2432 \
    frequency-mode=manual-txpower frequency-offset=0 hide-ssid=no \
    hw-fragmentation-threshold=disabled hw-protection-mode=none \
    hw-protection-threshold=0 hw-retries=7 l2mtu=2290 mac-address=\
    00:1D:0F:BC:66:B6 max-station-count=2007 mode=station-pseudobridge mtu=\
    1500 name=biuro noise-floor-threshold=default nv2-cell-radius=30 \
    nv2-noise-floor-offset=default nv2-preshared-key="" nv2-qos=default \
    nv2-queue-count=2 nv2-security=disabled on-fail-retry-time=100ms \
    periodic-calibration=default periodic-calibration-interval=60 \
    preamble-mode=both proprietary-extensions=post-2.9.25 radio-name=\
    urbilandia rate-selection=advanced rate-set=default scan-list=default \
    security-profile=default ssid=ZBYSZKO_3 station-bridge-clone-mac=\
    00:00:00:00:00:00 supported-rates-a/g=\
    6Mbps,9Mbps,12Mbps,18Mbps,24Mbps,36Mbps,48Mbps,54Mbps supported-rates-b=\
    2Mbps,5.5Mbps,11Mbps tdma-period-size=2 tx-power=23 tx-power-mode=\
    card-rates update-stats-interval=disabled wds-cost-range=50-150 \
    wds-default-bridge=none wds-default-cost=100 wds-ignore-ssid=no wds-mode=\
    disabled wireless-protocol=802.11 wmm-support=disabled
/interface wireless manual-tx-power-table
set compex manual-tx-powers="1Mbps:17,2Mbps:17,5.5Mbps:17,11Mbps:17,6Mbps:17,9\
    Mbps:17,12Mbps:17,18Mbps:17,24Mbps:17,36Mbps:17,48Mbps:17,54Mbps:17,HT20-0\
    :17,HT20-1:17,HT20-2:17,HT20-3:17,HT20-4:17,HT20-5:17,HT20-6:17,HT20-7:17,\
    HT40-0:17,HT40-1:17,HT40-2:17,HT40-3:17,HT40-4:17,HT40-5:17,HT40-6:17,HT40\
    -7:17"
set biuro manual-tx-powers="1Mbps:17,2Mbps:17,5.5Mbps:17,11Mbps:17,6Mbps:17,9M\
    bps:17,12Mbps:17,18Mbps:17,24Mbps:17,36Mbps:17,48Mbps:17,54Mbps:17,HT20-0:\
    17,HT20-1:17,HT20-2:17,HT20-3:17,HT20-4:17,HT20-5:17,HT20-6:17,HT20-7:17,H\
    T40-0:17,HT40-1:17,HT40-2:17,HT40-3:17,HT40-4:17,HT40-5:17,HT40-6:17,HT40-\
    7:17"
/interface wireless nstreme
set compex disable-csma=no enable-nstreme=no enable-polling=yes framer-limit=\
    3200 framer-policy=none
set biuro disable-csma=no enable-nstreme=no enable-polling=yes framer-limit=\
    3200 framer-policy=none
/interface wireless access-list
add ap-tx-limit=0 authentication=yes client-tx-limit=0 comment="HTC Magic" \
    disabled=no forwarding=yes interface=all mac-address=00:23:76:21:E5:24 \
    management-protection-key="" private-algo=none private-key="" \
    private-pre-shared-key="" signal-range=-120.120
add ap-tx-limit=0 authentication=yes client-tx-limit=0 comment=\
    "laptop - wlan" disabled=no forwarding=yes interface=all mac-address=\
    00:13:E8:84:1E:A3 management-protection-key="" private-algo=none \
    private-key="" private-pre-shared-key="" signal-range=-120.120
add ap-tx-limit=0 authentication=yes client-tx-limit=0 comment=kubic \
    disabled=no forwarding=yes interface=all mac-address=00:14:A5:DA:75:5D \
    management-protection-key="" private-algo=none private-key="" \
    private-pre-shared-key="" signal-range=-120.120
add ap-tx-limit=0 authentication=yes client-tx-limit=0 comment=grzesiek \
    disabled=no forwarding=yes interface=all mac-address=00:26:E8:C0:E3:93 \
    management-protection-key="" private-algo=none private-key="" \
    private-pre-shared-key="" signal-range=-120.120
/interface wireless align
set active-mode=yes audio-max=-20 audio-min=-100 audio-monitor=\
    00:00:00:00:00:00 filter-mac=00:00:00:00:00:00 frame-size=300 \
    frames-per-second=25 receive-all=no ssid-all=no
/interface wireless sniffer
set channel-time=200ms file-limit=10 file-name="" memory-limit=10 \
    multiple-channels=no only-headers=no receive-errors=no streaming-enabled=\
    no streaming-max-rate=0 streaming-server=0.0.0.0
/interface wireless snooper
set channel-time=200ms multiple-channels=yes receive-errors=no