I am having similar issues with my new HP Envy which uses a Broadcom card. All other devices connecting fine to Virgin's (Netear) Superhub.
Although all other devices remain reliable, ALL devices have issues loading Superhub pages when Broadcom is brought into the mix.
From what I can gather there is some vendor compatibility issues. This is quite similar to when I introduced an Acer with Centrino wifi my Draytek Vigor 2800, which actually killed the Draytek completey after a few mins, Same household, same device otherwise.
Very frustating. Will update this thread if I find a solution.
OK, after a lot messingabout (inc. compiling Broadcom firmware in Ubuntu 10.02.2 LTS!) the solution for me seems almost embarrassingly simple: Keep trying different channels.
The link quality from the laptop is still far from ideal, with a very fluctuating 1 - 250 ms ping to the AP, whilst the signal strength has remained at 100% throughout. All along the laptop and AP are almost in contact, so something is obvkiously still seriously wrong here and I have a bad feeling my connection quality will start to deteriate soon (probably when a neighbour switches channels on their AP!)
Interesting to note that all my other kit (inc. Dell Vostro, Acer Aspire, Nokia N900, all NOT using Broadcom AFAIK) have consistently kept solid connectivity to the Superhub AP, with no reason to tweak any settings etc.
I had initially ruled out channel conflicts or other radio interference, as I have always used the least populated & overlapping channel and even tried to replicate the issue from other devices, in various locations.
So it looks like the particlar model and revisions of Broadcom & Netgear kit really don't get along too well, at least in an environment with a fair number of other APs in the neighbourhood too.
I notice you said you have already tried all available channels Daren? I wonder if your root cause may still be the same but in your particular case you simply have more wireless APs around you.