Have you tried a recover of your file to check it for damage?
If you place a portal to the related table on your layout, it should list the same values as your conditional value list. You might put one on your layout and see if it updates in the same manner as your value list or not.
Okay, I ran a recovery and it showed no errors. I restored it to a version from before our server crash and it exhibited the same behavior. So I'm ruling out file damage for now and moving on.
I'm a little twisted around by which instance of the related table I should use to setup the value list. Your suggestion forced this. Setting up the portal demanded I ask which related table or which instance of a related table I use and which relation should constrain the value list records. I have some poking around to do once my head is screwed on straight, but I think that is the source of my issue.
There must be a medical name for this condition where visualizing a complex database's relationships render a Friday mind utterly useless. Back next week. Thanks.