After nearly a year of faithful service my MacBook developed the dreaded WiFi connection dropping syndrome. It started happening shortly after upgrading from my old faithful Linksys WRT54GL to a shiny new D-Link DIR-655. At first it happened sporadically, but gradually the condition worsened until the connection was sometimes dropping within a couple minutes of being connected and sometimes even less. I tried every fix I could find on the Internet short of downgrading to Tiger from Leopard. In the end the only thing that worked for me was turning off 802.11n in the router and restricting it to 802.11g only.
I am not too unhappy about losing 802.11n. But I bought the DIR-655 primarily to upgrade my home office to Gigabit Ethernet so getting 802.11n was really just a bonus feature. Even so, I am still hoping that the impending release of OS X 10.5.2 fixes the problem so that I can turn 802.11n back on.