What were your prior experiences with wifi and your router?
Where is the AP located in relation to the lappy?
Any one talking on a cordless phone at the time you are running the laptop?
Have you tried changing channels?
Lastly, FWIW a long time ago I had a D-Link 802.11B AP and it was horrid. An external Orinoco card (which are awesome in terms of wifi) had a really hard time picking it up. I'd get half signal strength everywhere. Tried different cards and no luck. Ordered an internal card for my Toshiba and it was an Orinoco chipset too, but had the advantage of the laptop antennas built in and it was still bad. Changed routers to a Linksys WRT54G and I had no problem getting full signal. Some products have weak-sauce radios in them and therefore are partially deaf or partially mute (thats the easiest explanation I can give you) so wifi appliances can have a hard time picking them up.
Try going to a coffee shop or another known wifi hotspot that is operating normally and see what it is like there.