langsomt wlan mandriva 2009

mit wlan er meget langsomt i mandriva 2009
wlan kort rtl8187b

nogle som ved hvad det kan skyldes

iwconfig

wlan0 IEEE 802.11bg ESSID:"UBUNTU"
Mode:Managed Frequency:2.437 GHz Access Point: 00:B0:0C:03:19:7F
Bit Rate=54 Mb/s Tx-Power=20 dBm
Retry min limit:7 RTS thr:off Fragment thr=2352 B
Encryption key:726D-644D-3E Security mode:open
Power Management:off
Link Quality=100/100 Signal level:-17 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0