After a couple of highly publicised videos on YouTube that showed two separate incidents of Inspire 1’s taking of and then heading rapidly sideways, DJI appear to have acknowledged that there is a bug after analysing data from the aircraft involved. The flagship quadcopter has been well received and attracted large volumes of pre-orders, now finally being fulfilled after a delay in getting product shipped. However there have been several reports of quality control issues with the manufacture of the aircraft, and reports of instability in the hover, as well as the two videos.
In this forum post a DJI support staff member showed one of the videos and acknowledges the issue is with the IMU. DJI will be issuing a safety notice until they can roll out a software fix, but it appears that you need to carefully check your IMU “mod” values before a flight, and if they are outside a narrow tolerance then you need to recalibrate before taking off.