Hi Jeff
The only real explanation I can fathom is that perhaps where
the links worked without issue, you had maybe used the image in a
topic as well. That's the whole issue in a nutshell. If you use an
image in a topic, RoboHelp is aware of it. But if you only link to
it from a popup, it needs to be added to Baggage.
Adding to Baggage won't hurt anything if you are unsure.
Cheers... Rick