Good grief - what sort of a building do you live in ?
I have a 3Com router/access point/adsl modem/firewall box and use 3com cards in our laptops - I have no problems with connections or connection speeds anywhere in the house. One of the laptops is running SuSE 9.2, the other Windows XP.
We also have DECT phones, cordless headphones and, occasionally, a bluetooth connection to my mobile running, so it isn't a pristine environment radio-wise. The internal walls are mostly plasterboard, except for the room where the access point is and the room where I usually use my laptop, both of which have breeze-block walls all the way round.
I would suggest taking a good look at what else you have running within a couple of feet of your access point that might be generating interference !
Hope this helps,