Can’t see other devices on the Wired LAN with your WR841N, even though those devices can reach the internet? Can you see those devices on the ethernet from the wireless LAN?

If you have this problem, it might be that you’re affected by a bug where the local ethernet VLAN hasn’t actually been enabled. I at least ran into this as of r24461, but the fix is reasonably simple:

swconfig dev eth0 set enable_vlan 1
swconfig dev eth0 set apply

If you’d rather not type this every time, you can do:

nvram set rc_startup="
swconfig dev eth0 set enable_vlan 1
swconfig dev eth0 set apply
"
nvram commit

Alternatively, it appears that r23919 is a working build, based upon this thread.