Posts removed from Facebook wall when updating WP post

When I update a post in WordPress and uncheck “Post again to Facebook”, the wall post on Facebook gets removed .. including any comments that were attached to it.

If I go back into WP and check “post again to Facebook”, the post shows up on my wall, but the comments tied to it were lost.

Is this by design, or am I doing something wrong? I want to prevent multiple wall posts or notifications to friends if I decide to go back into a WordPress post and edit it for grammar, photos or whatver.

Thanks ..