AFAICT there is absolutely nothing wrong with either my code or with HoloEverywhere.
For some inexplicable reason those devices sometimes seem to lose the Holo.Theme attribute from the Activity's style. This causes HE to throw an Exception.
In case anyone else falls into this error this is the work around I am going with.
@Override
protected Holo onCreateConfig(Bundle savedInstanceState) {
final Holo config = super.onCreateConfig(savedInstanceState);
config.ignoreThemeCheck = true;
return config;
}
As this will cause HE not to check that a a HE theme has been defined.