I get this so much that it it the one thing I really can't take about my Macbook. It happens to both my original one and my replacement. It definitely happens more frequently at home. We are talking about every 15 - 30 min. I have to keep doing "Join Network", re-entering my SSID then log in. This is crazy. Meanwhile we have 4 Thinkpads that never drop the signal so it is clearly the Macbook.
I am running a Dlink DI-524 with WPA-PSK and no SSID broadcast. Do I need to change some of the router settings? Getting desperate here. I am even thinking of trying to change my router/AP.