[Lilux-help] WLAN range problems

Hi everyone, currently I'm replacing my old 10Base2 ethernet at home with a 802.11g WLAN. I'm running into some range problems. The hardware is the following: Allnet 0271 PCI cards (supported by stock 2.6 kernel, yay) SMC 2802W.V2 PCI cards (supported by ndiswrapper only, shame) Linksys WRT54GS Router (nicely hackable) The trouble is that the PCI cards are unable to connect wirelessly, even though the distance is less than 10 meters. There are 2 walls inbetween the PCs. The house was built in 1974, and I'm not sure if any steel-reinforced concrete has been used. Some experiments have shown that as long as there is an approximate line of sight between any of the components, things will work somewhat, although the range is still bad ( > 50% packet loss at less than 10 meters distance). Curiously, a Centrino-based laptop (802.11b) gets "great" range (> 20 meters). I've tried forcing the whole WLAN to 802.11b, but that doesn't seem to help the PCI cards. I've tried changing channels, toggling encryption, etc, but nothing helped. Does anyone know if replacing the antennas on the PCI cards might help? Has anyone tried some? There are also active antennas (http://www.lirr.net/BA24.htm for example), which might work well, but they are a bit pricy (119 USD for this model). Or should I try to send the cards back and get a replacement? Any help is greatly appreciated, Christian Glodt