Anyone got any ideas on how to fix this?

I updated my SD to 3.2.1.0 last week for a trip yesterday, both on my laptop and my Windows Mobile device (old school, I know, but it works).

Everything works fine on my mobile device except the compass rose is now replaced with a red X.  The navigation still works fine, in the GPS pages the software still knows what the Track I'm doing is, everything except the compass rose (and the Instrument display, if I choose that) works ok.  Any ideas how to fix the HSI bit?

OK, sort-of fixed myself.  By choosing tracks to be shown in degrees True rather than degress Magnetic, the problem goes away.  This is not a setting I've changed recently.  Has the variation calculator/database been removed and Magnetics tracks now unsupported?

Thanks for reporting this; we will look in to it. There was a recent update of the magnetic declination model which might be causing what you are seeing.

Thank you, Tim.  Yep - that would explain it.

Not a show-stopper so I'll continue with °T until the future fix.

I can confirm we've been able to reproduce this. We will get a fix in place for the next version update. Thanks for reporting it to us.