Ok i have very similar problems however this is what i have found thus far.
Wifi Nic = Intel(R) Wireless WiFi Link 4965AGN
OS = Windows 7 64bit
Routers = Linksys Wrt 600n; Linksys wrt 160n & Belkin Enhanced N
Problem = downloading or VOIP connection drops but resets itself after about 2 min. Needless to say when using VOIP for business this becomes very irritating. So started off looking at the router as the source of the disconnects but after using 3 different routers with the same problem i started doing some traces from a 2nd laptop.
the result was that as soon as i started downloading using the intel wifi nic the router got flooded and dropped all connections from all sources. I tried all the methods about ipv6, usb and bluetooth updated the firmware of routers nothing helped.
I then tried using a usb sitecom n wifi adapter and all the issues are gone. I have not had a single drop since i switched to this nic and i have downloaded roughly 60GB over the last 10 days from the office server.
So by process of elimination the culprit has been identified as the intel 4965 agn adapter. I can recreate this issue at will and have tried every single win 7 driver from intel still the problem persists. As this is a laptop I even tried speaking to Acer and the driver that they provided has the same problem.
I believe that this is a driver issue but it doesn’t seem that either intel or acer for that matter is interested in fixing this issue as they can find to many 3rd parties to blame.
Sorry this not a solution to the problem but I thought I would post my comments so that people can verify my findinds.
Cheers happy new year