I have router D-link Dl-524

My wrilless card D-link DWL 520+ in my computer can not be faster than 1 Mbps by signal strenght 80%

WHY? Help if You can

Max speed in this card - 22 Mbps Speed in router - I chose 11 Mbps

DWL worked in 22 Mbps in other router.

ps Notebooks have speed 11 Mbps in this WLAN.