Also, this router is REALLY sensitive to positioning! I have got drastically different results depending on where I place it, even from items in the next room. Something as simple as a piece of furniture in the way can change things. I now have it on the wall at about 4 feet with the aerials pointing in slightly different directions.
There are some advanced options also (especially the 801b network guard) that you can fiddle with, but I would warrant that yours is most likely due to environment..... unless.... it's the old deathentication problem, in which case I wish you luck.
I would advise taking a close look at the wireless drivers on the laptop. If you wanted more feedback/help it would be good if you could let us know what the wireless adapter chipset is on the laptop and whether or not you have windows managing it, or the producing manufacturer manager (i.e. a dlink wireless manager on the laptop), or the chipset manufacturer wireless manager. For example, I have an DLINK usb N adapter on my main machine but I use Ralink driver to manage wireless much more sucessfully, I have an intel chipset wireless on one of my laptops and intels "zero config" wireless utility is notoriously hopeless at keeping connections, so I get far better results using the Win7 OS wireless manager, etc.
Post some more details and let us know how you get on
