I have the same issue as stated here,
i followed the horizon calibration tip but it doesn't help...

http://forum.basecamelectronics.com/index.php?p=/discussion/2292/beholder-ds1-problem/p1

Anybody has an idea ?
I tried repeating the process a few times by switching on, calibrating horizon, switching off, turning on, calibrating, etc...
as I read it worked for someone on another forum...

Any help would be appreciated because this is driving me crazy and makes the gimbal unusable...