I created the eyelids from a sphere and in the shpere property page turmed the V start to 90, making an eye lid. I then postioned it over the eyeball and scaled it slightly bigger, then I duplicated it for the botttom one. The two lids are linked to a parameter slider for which I have set rotational values at open and closed positions.
The lids are parented to the eyeballs, but the eye ball have no keyframes on. they are constrained in Z to a set of nulls which I keyframe to make the eyes move. The eyes are a child of a bone which is a child of an implicte eye cube whith no keyframes on. But the eye cube is a child of the neck cube which does have rotational keyframes on. And looking back on saved versions it is only on scenes forward of when I started rotating the neck cube that the problem starts.
Hope this makes more sence.