I also run an NDS, Wii, and Laptop on the wireless network all without any trouble.
I suppose I can try the beta firmware as a last resort. I’d be surprised if something was with DD-WRT, it’s been doing a fine job for me and like I said, it was working alright before and I haven’t changed anything on the router since.
The only thing that happened that I can think of which even remotely might have some effect is that there was a round of security updates to the Avahi packages that I did… but why should that effect Firefly running mDNS?
I even tried disabling Avahi in my Ubuntu services control but it didn’t make a lick of difference.