That is rather strange, but happy to hear you managed to connect to terminal, I totaly forgot to mention about the buad rate issue! . Once connected to terminal you could also try to run the accel calibration by typing:
However here are some other suggestions you can try.
1 - We had a similar error from another customer which was caused by them using the wrong GPS cable, easy mistake as you need to use the 6pin cable, and not a 5pin one which you use to connect the GPS to APM.
2 - I am finding it abit hard to read the values from the INS test in the terminal but one more thing to check - once you have connected to your board with mission planner is to check the flight data (located under the status tab below the heads up display). On this screen check the az value when your board is level you should get a reading about -1000 +-100, assuming you have not yet calibrated your accelerometer. If you are getting something significantly different please let me know.
3 - Lastly one more thing to try would be to format the SD card, and load another firmware onto the board, if you are using arducopter, try load arduplane and then go back to the arducopter firmware just to make sure everything has been written to the board correctly.