Like apparently most forum-dwellers (except David), my hotspots feature used not to work.
Well if I do exactly the following, it does:
-Launch Lugaru
-Enter Challenge 1
-Enter map mode
-Enter "hs 15.0 0 tweep" (it works!)
-Open my custom map
-Now hotspots work in my map
All kinds of very subtle variations along this line do not succeed, for no apparent reason. Some do.
Hope this works for other people
EDIT: Ok, bad news:
1) The above tactic doesn't work anymore for me, but a slight variant does. Experiment to find what works for you today.
2) Also, the text for the hotspot can randomly be accepted or rejected.
However, good news:
1) Once you get a hotspot to work, it will always remain operative
2) If you have a hex editor, you can easily change the text of an existing hotspot by overwriting the old one, and setting the byte just before the string to the number of its characters, +1 ('cause there's a line break at the end). This pretty much cancels the bad news item n°2.
Conclusion: patience is the key, but it works