Dear Opus,
I created a small project, with one cmd button on a single form. I created a tiopic in an htm file, an Alias section & a Map section. I was able to open the help file with F1.

I created a text file with one topic and an h file with the context assignment. It never maps the number to the topic!!!

I tried multiple insertions of the .h file. I tried puting the def in the Map section. No way!! It absolutely refuses to make the connection!
The docs tell us to put the map information for the html topics in the .h file. That absolutely will not work, so I doubt that it will work any better for pop up topics. For blessed sure it ain't working for me!!! Is there some obscure detail you ommitted?? Could you post your sample app & help project files so we can see exactly what you did to make it function???