Note that I tried to use WICD instead of network manager and I have the same issue. The only difference is that WICD tells me that I am disconnected when my connection drops. Network manager on the other hand tells me that I am still connected. Reconnecting fixes the issue (temporarily)
I don't have that problem at all when I use an ethernet cable.
Finally, this problem only started to show up a couple of months ago, before that everything was working fine with 12.10.
Note that I tried to use WICD instead of network manager and I have the same issue. The only difference is that WICD tells me that I am disconnected when my connection drops. Network manager on the other hand tells me that I am still connected. Reconnecting fixes the issue (temporarily)
I don't have that problem at all when I use an ethernet cable.
Finally, this problem only started to show up a couple of months ago, before that everything was working fine with 12.10.