If you have Linksys by Cisco - WAG54G2 and want to share the DSL internet connection by WLAN to many PC's you probably will face the problem that only one PC will get proper internet access while the other ones have very slow connection.
How to solve it? Since QoS implementation on WAG54G2 is very bad or poor, there is no way to resolve this by a software setting on the WAG54G2.
Instead you can use your old WLAN routers (if you have - or buy cheap new ones ...) and connect these routers to the WAG54G2 by Ethernet wire and setup a separate WLAN for each WLAN router and let each PC connect to one WLAN router only.
At least at my home it is working perfectly since several weeks. Hope it will work for you as well !!!
Why it makes such a difference? I really don't know ... ;-))