Disconnection Problem with DWL-G650+ Wireless Card

Hello,

I have a downloading problem with my D-Link wireless cardbus adapter
DWL-G650+ which I'm using with my Fujitsu-Siemens Laptop. When I try
to download very large files, the card downloads to a certain point,
then the disconnection message box appears for a few seconds after
which the wireless internet connection is re-established and the
downloading continues. This can happen a few times when I'm
downloading a file of say 120 MB and normally wouldn't bother me, but
it sometimes happens that the files I'm downloading cannot continue
from their disconnection point and I'm forced to try to download them
again from scratch.

At first I thought the problem was with the access point but then I
tried downloading at a different one and had the same disconnection
problem. I looked up the settings under Windows XP and it shows that
the card is working fine and there seem to be no hardware conflicts.
The built-in LAN card works fine when used with a cable for
downloading. Can anyone advise what is the problem here and how I can
overcome it???

Thanks.

Khan