HostAP fine, but no traffic

[Thomas Sturm]

Hi there,
I just set up HostAP on my Debian/Sarge box and everything seems to be
fine, I can log into the Wireless Network, and I receive an IP address
from dhcp via wlan0. But after that, the Wireless connection is just
dead, I even can't renew my IP via dhcp, no ping is sent. When I reset
wlan0 I receive a new IP from dhcp, but after that the connection is
dead again. Can anyone tell me whats the problem here? Please tell me
which logfiles or whatever you need! 
Thanks,
Thomas