I read on http://www.grainge.org/pages/authoring/browsers/browsers.htm that this was fixed in RH 7.0.2 - did the fix not make it into RH 8.0??
If you import the topic with the hotspot and the topic that is the popup into a new project, is the problem the same?
If it is, send me the new project. See the contact page on my site.
Doubt I can fix it but I'll understand the problem better and can see if it matches others seen.
See www.grainge.org for RoboHelp and Authoring tips