i'm currently researching this problem and found that if i change the firmware(rt2870.bin) to a different one i am able to see wifi networks but can't connect to my wpa2 network. Try to install firmware from here http://www.mediatek.com/en/downloads1/downloads/ . It's located in /common folder. Copy from /common to /lib/firmware/rt2870.bin and restart. When using the adapter check "dmesg" it will show you which firmware version you are using. The one i provided you is v33, here https://packages.debian.org/search?k...irmware-ralink is version29(0.29). Currently i'm testing so when i'm done i will write here if i succeeded
