I have other wireless devices using the same AP with no problems, and the same laptop performs well when booted into Windows, so this appears to be a problem with the bcm43xx drivers. I keep hoping that each kernel update will improve the situation, but so far in vain.
b43 is great with the 4.x drivers from openwrt in 2.6.24+ on fedora. however i did more tinkering yesterday. Turns out the problem is with my isp - sometimes i hate being in the uk. Tried ssh -Y on another local machine with different public ip address and had the same problem so it isn't the laptop. i then set up an instance of CentOS5 on amazon's ec2 service (love that btw) i then ssh -Y firefox using that instead Even with the trans-atlantic roundtrip and through the encryption/decryption it was nice and responsive compared to a local copy. Partner now happy as she can browse next store online without getting upset. :-)
Time to change providers, thinking of zen adsl or andrews and arnold.
wpa_supplicant seems to work well for me using WPA2-personal
sorry for the noise
mike