Cannot calibrate compass in MP

I have just upgraded an apm 2.5 to use an external compass/gps and fitted it to my new Tarot, but cannot get it to calibrate in MP.

Track is cut on the APM and I can prove that is done properly 'cos without the external compass attached it does not work when viewed in MP. Attach the external compass and the compass works in MP, with correct orientation etc.

BUT, come to calibrate the compass (do the compass dance) and MP flatly refuses to do it. Nothing, nada. I press “live calibration” and I do not even get the sphere with the dots showing. I start waving the machine around but still nothing. MP is 1.3.7, APM is latest 3.1 firmware for hex

I’ve done this loads of times before. I’ve reloaded the firmware on the APM and rebooted MP but still nothing.

Anybody have any ideas? The only difference that I know of from when i have done it before is that there have recently been some Win7 updates.

Thx

do you get an error?

something like this?
Exception System.TypeInitializationException: The type initializer for ‘OpenTK.DisplayDevice’ threw an exception. —> System.ArgumentOutOfRangeException: Must be greater than zero.
Parameter name: width
at OpenTK.DisplayResolution…ctor(Int32 x, Int32 y, Int32 width, Int32 height, Int32 bitsPerPixel, Single refreshRate) in c:\temp\opentk\Source\OpenTK\DisplayResolution.cs:line 39
at OpenTK.Platform.Windows.WinDisplayDeviceDriver.RefreshDisplayDevices() in c:\temp\opentk\Source\OpenTK\Platform\Windows\WinDisplayDevice.cs:line 132
at OpenTK.Platform.Windows.WinDisplayDeviceDriver…ctor() in c:\temp\opentk\Source\OpenTK\Platform\Windows\WinDisplayDevice.cs:line 45
at OpenTK.Platform.Windows.WinFactory.CreateDisplayDeviceDriver() in c:\temp\opentk\Source\OpenTK\Platform\Windows\WinFactory.cs:line 92
at OpenTK.DisplayDevice…cctor() in c:\temp\opentk\Source\OpenTK\DisplayDevice.cs:line 68

No, no error message, just sits there waiting for me to move the hex around, which I do but it doesn’t see it happening. I can cancel it and do other stuff so MP in general seems to working.

Do you think I should i re-install MP? I got to thinking that maybe the Win7 updates that have loaded since the last time I used MP have somehow corrupted my MP install, but I don’t know enough about s/w to even know if that is a sensible thought.

Cheers