theme not accepted?

[Bernard Aak]

Since appr one year I am using prestashop 1.2.5 with pleasure.
For different reasons I wanted to investigate about another theme than the usual theme.
I downloaded a theme, uploaded it to my themes/ folder and it was after that visible
in my backoffice under preferences/appaerance. I clicked the new theme and saved
the action. It was then accepted. However it was not clicked on as I looked back and
my usual theme was present (with click) so whatever I try the new one can not
be activated. What can be the reason of this behaviour?
Kind regards, Bernard.