Ringfinger, I feel your pain.
I've been fighting this for the last year with my WZR-HP-G300NH.
I've come to the conclusion that the router likes to drop bonjour traffic over wifi and the only way to get it going again is a restart. I like the soft reboot idea, I usually just walk to the router and unplug it, plug it back in and curse for the duration of the lengthy startup. Which page are you using for the save/apply?
Here's my setup and situation.
Hardwired to the router (through a Trendnet gigabit switch off of the router) I have a Mac Mini, a Windows 7 Nettop, a Canon Printer and an AppleTV 2.
Using the wireless, I have a Macbook, 2 iPhones and 2 iPod Touches.
Bonjour services between the wired devices are always available. I can send Airplay from the Mini to the AppleTV, Print from the Mini to the network printer, so on so forth.
Wireless is another story. Periodically the router flakes and none of the wireless devices see the bonjour services on the network. The iPhones and iPods can't send Airplay to the AppleTV, print via Airprint, sync wirelessly with the MIni. The Macbook can't see the AFP share on the Mini, can't screenshare, can't print to the Canon, etc.
The Macbook can still see and access the Samba shares on the nettop and the Mini, so it's not a wholesale issue of wireless devices not being able to access wired devices on the LAN.
It's totally intermittent and terribly frustrating. It can work fine for weeks or require daily restarts. I've fiddled with the multicast settings, reset the router to factory, set all the ip addresses manually, let DHCP assign ip addresses, cursed, begged and pleaded to no avail.
I don't know how traffic is routed through switches, so it might be luck that my wired side works fine because it exists on a switch away from the Buffalo. If it would be of any help, I could plug some stuff directly into the router to see if anything on the wired side changes.
I sure would like to see it fixed because I'm too cheap to buy another wireless router and too hesitant to install DD-WRT (I don't want to trade one problem for the potential of another.)
cgrebos