Couldn't stop searching for the cause of the problem....
After trying all kinds of little changes to the panel, like adding a <div> or ";" here and there, I accidentally changed the theme to Gillette.
And guess what? No problem anymore...
I checked all the v7 themes that I have and here are the results:
2point0 fault
Aer fault
Atlantis fault
Fumaeleon fault
Gillette good
Pastel fault
Phos fault
Similitude06 good
Similitude07_div good
Simplicity_div good
So there seems to be a problem in the newest themes, because the themes Gillette and the last three are the oldest v7 themes.
Thanks ... very interesting .... but i am not wondering ... in my mind, all the new themes, exclude the gilette and the other olds are ok ... but the other styles are