I have a weird problem. I connect my Pi via WiFi to my network via wpa_supplicant. I get an IP adress via dhcp and my Access Point show the RPi in its connected devices list. When I try to ping/connect to it from my Windows PC I get a "host not found" error. But when I ping my pc from the Pi and let that ping running ("ping 192.168.178.21") I get a response from my Windows PC and I now I can ping/connect to my Pi with my PC. When the ssh connection (pc->rpi) is in idle and I stop the ping on the RPi then the ssh connection closes and I am again not able to ping or connect to the rpi. I have no idea where to start looking for that problem. I already tried disableing the power management (iwconfig wlan1 power off) but that did not change anything. I am using raspbian and a "Ralink Technology, Corp. RT2870/RT3070 Wireless Adapter"