I bought some netgear wireless PCi cards & wap, for some reason it kep dropping the connection every 30 seconds or so, I sent the stuff back after trying everything including updated firmware. If your problem is signal strength an external antenna from Jaycar for around $20 may improve matters. If the problem is signal then a high gain antenna or more powerful access point may help.
Freenet Antennas have an excellent range of gear and Terry in Sydney is very helpful, may be worth giving him a call.