I have a strange problem with my APM1 2560.
If I load the arducopter code the compass works completely as expected.
If I load arduplane 2.40 code on the same APM then the compass keeps coming up disabled.
I can set it to enabled but when I next connect it is not enabled again.
If I try and test it from the CLI prompt with arduplane loaded is says it is disabled.
With arducopter loaded it tests fine.
Anybody any have any idea what is going on here?