Please be gentle with me as I have only limited technical knowledge!
We have also begun to experience this problem with iPlayer.
We are running three machines wireless on a Speedtouch 585 v6 - one desk top with a Speedtouch dongle and two laptops wifi ready. One laptop is only a few months old, mine is two years old but my son's desktop is five years old.
Yesterday (maybe due to recent upgrades on the BBC site?) he has started to experience problems.
After a minute or so of streaming on his desktop, the Speedtouch router goes down and displays only green lights - its takes quite some minutes to reboot.
Last night, all three machines were in use when the router crashed and rebooted and we wondered whether recent upgrading of the BBC iPlayer means that it now requires more bandwith than before and is struggling to stream with all three of us online at the same time.
Today, we tried my son's desktop with iPlayer for a Radio 4 programme with neither of the other two machines in use. Same problem - would stream for a minute or so, then router goes down, just like last night.
My son's five year old desktop has only 250 MB RAM installed and I wondered whether low memory might be a contributing factor, or because he is using a dongle and is situated upstairs - though his signal is usually strong.
The other two laptops have 1 gig of memory installed, are wireless ready and used downstairs where the router is situated. We are all running WXP or XP Pro, all with SP2.
Within the last two weeks, my son has installed Norton A/V 2008, and does not run a FW (only the FW in the router).
Prior to this particular problem, we would occasionally drop the connection when not streaming media but the router would pick up the connection again almost immediately.
This problem with iPlayer seems to produce a particularly distinctive reboot in that it takes longer to reboot.
The reason I mention the lower memory in my son's desktop is because this morning we tried iPlayer from the BBC site on my latop and although we only let it run for 10 minutes or so, which probably wasn't a very fair test, we experienced no problems - as I say, I've got 1 gig on this laptop.
The two laptops run Kaspersky A/V 7 with Zone Alarm Free (an older release, not the most recent incompatible with KAV version) and AVG free with Zone Alarm free (latest version).
Our BRAS profile flaps every few days between 2000 and 4000 and router stats average around 4,600 though sometimes dips lower than 3000.
We bought the Speedtouch router through Zen last November and have not updated it.