This is old post:
Since firmware update Finless ROM 1.7 WiFi issues is fixed.
A simple way to fix WiFi issues with UG802 (remove antenna outside the case)
1. Open your UG802 with a plastic opening tool or guitar pick. Be careful not to break your clips.
2. Using sharp knife make/cut a hole on the case. Make sure WiFi wire is not pinched.
3. Remote WiFi antenna outside the case, or way from USB port.