My understanding is that this is not uncommon among Coolscan V and LS-5000 users, since I think they have similar (if not identical) optical paths.
I don't have links, but there are at least 2 fairly involved discussions on photo.net that describe this phenomenon (Searching LS-5000 and ghosting should get you to them). First thing, make sure the 45-degree mirror below the slide stage is absolutely clean. There are instructions online for how to do this. Cleaning it could make the flare less bad, but probably not make it go away. Make sure you're using the absolute minimum scanner exposure level needed for that image, and try re-orienting the slide so that the ghosts go a different direction and are less noticeable. Short of custom modifications to the optical path, like those discussed in one of the photo.net threads, I'm not sure that there's much else to be done about it.
Here's a good example I personally witnessed with a Stouffer step wedge. (Note: Step 20 is ~3.0 logD, and the clear text is ~0.06 logD, a pretty extreme example, but probably not too far off what Lamar is seeing with the specular highlights in his images.) The upper half is the straight scan, and the lower is after an aggressive, but not unreasonable, IMO, levels adjustment in PS.
Sorry I can't be more helpful.
--Greg