GK5: Control Panel corrupted and Error: No articles to displ

Hello,
i tried multi nsp gk5 2.5's installations even in totally fresh Joomla! installations. I ever get the same 2 problems:

1. The module's control panel looks corrupted: i can't see the graphical look (like other GK components in same installation do) but a lot of panel's code spread. Anyway I can insert options and choiches (but sort field).

2. I ever get Error: no articles to display if in standard mode, or a totally empty space (in web page) if in any other mode (for instance News Block), even i tried as much i could, choosing all available article sources, played with time offset, and so

Joomla is 2.5.19

I Sent to Cyberek a PM with site address and administrator's username and password.

TIA
Lupo

Is there anybody to help me? i can PM admin credential to whom asking me
TIA

I tried now to install GK Tabs, when i try to configure it the tabs panel looks empty,
I don't get a clean GK interface, it seems that my joomla installation doesn't fit, it's 2.5.19, the last release....
TIA