Hi,
I investigated this problem a bit futher:
apparently when I lose my internet connection (I'm still connected to my AP at this point), it's my DNS that doesn't work anymore. DNS settings for my client are dynamically assigned by DHCP on my pfsense box. An ipconfig /all showed me that the DNS server is 192.168.6.0 (shouldn't this be 192.168.6.1?). In the DHCP server settings in pfsense I left the DNS entry blank.
I did a ping to a website from one of my stations that has a wired network connection, and I received answers. When I lost internet connection (again my connection to the AP was ok) I did the same ping and my wireless client couldn't resolve the DNS name. I tried to ping base on the IP address of the website and I received answers. Also surfing based on that IP proved to work.
The strange thing is when I switch of my wireless nic and reconnect the problem is gone (for some time). So it would seem this is a client side issue. However I have 5 different wireless clients and they all have the same problem since I switched to 1.2.3.
I'm running the snapshot from 25feb at the moment.
Best regards,
Jan