I have the same issue that my wireless connection drops when there is 'heavy traffic' going from WAN -> Wireless
I can start downloading at 2MB/s but after 5 minutes or so, the connection drops. I can still see my wireless access point, but i can't connect to it. The only thing I can do to solve this is accessing the webgui and reapply the wireless settings using a wired connection. When I restart the download again, after 5 minutes the connection drops again.
I'm running 1.2 on a Linksys Ralink card. My laptop is the only wireless client in my network.
I think somehow this must be driver related? I tried 1.2.1 and 1.3, then I can configure my wireless but I get 'no carrier' on the interface status page so I presume the Ralink drivers are not mature yet on freebsd7?
I tried with another wireless NIC (also ralink) to eliminate a faulty wireless card, but I have the exact same issues with that card.
I hope there will be a solution to this rather soon, because in this state I can't put Pfsense into production.