Hi Peter,
I noted that you're using cfitsio v3 and the ubuntu 15.x has v2 as standard so I had a look on the nasa site for an update, now v4 there's a comment about a critical bug fix. Not sure of the details but I've symbolic linked the v3 shared library into a 4.x and it seems to work.
Ekos and many of the other drivers (especially those that use a static version) may be impacted.