I have sigpro installed and it works great except for one annoying thing.
I have a site with a few galleries on different articles and when I click the pop-up images in one article it works like a charm but in the other the pop-up window displays another header (caption style) the correct one is a h3 header but in the newer one it's another formatting.
See both sides here and click one image to see the difference:

Gallery 1 (correct)
Gallery 2 (erroneous)

How can I solve the problem?

The gallery with the styling you like is a result of a conflict with your template css. Turn your site to the default joomla template to verify this...

Thanks for replying!
I tried to set default template rhuk_milkyway and the problem remains, nothing different than before.

My idea was that there was something to set in SIGPRO parameters but nothing there either.
This is soo confusing.

Ooops! I found the problem...
I had set the <h3>Header</h3> in the labels.txt file... sorry for being so blind... :-[