The card in question has a very good range. so if your access point does not have an external antanna or is placed in the wrong place you will have problems.
Place the AP as high in the house as possible, if you are using the HP WL510 system then you can buy a Range extender antenna with about a 5db gain from HP or ? which will also connect to the WL110 card in your pc.
If you are using Lower end type AP location is about the only thing that can help you.
If this is at the office you might request them to maybe move the AP a little closer or expand their coverage by adding another AP.
For more information see the web page:
ftp://ftp.compaq.com/pub/products/wlan/WLANOverview.pdfRemember the Antenna only works in the Compaq Access Points: WL410, WL510