Intel Wireless 4965AGN can't connect to "heavily used routers"

[AegisTalons]

So I'm running Ubuntu Hardy with a intel wireless 4965AGN. I did not install any extras drivers. I just did the Ubuntu install via the alternative method and wireless normally works. At my house, it works with the WPA on and Mac filtering enabled.

Yet on campus (college), I'm having issues connecting to the internet in certain areas where there are a lot of people (University Center). Yet, when I reboot into Windows, I can get the internets. In Ubuntu, I see that I'm connected to a router and have about 90% signal.

Any recommendations from the community? I know about this site: http://intellinuxwireless.org, but I'm not sure if that would solve my problem, and I don't want to try for fear of losing the internet connection that I already have.

[AegisTalons]

Does anyone know what I'm talking about? Does this situation happen to you in Linux but not in other OS even if you don't have the same wireless card as me?