[Plugin: Hover] Can’t get it to work

It seems that i have an error and Hover doesn’t work properly. Some more info:

The problem:
In post pages the words are underlined and all, but the popup doesn’t appear. Here’s an example post (http://www.gabrielboaca.ro/2010/01/03/reclame-auto-de-efect/) and you’ll see what happens if you mouseover on “Romania” word.

What I’ve done:
Just copied the Hover files in the Plugins directory and activate it from the Admin

Additional Info:
1. The Hover config page in Plugins looks like that (http://bit.ly/7GMdLR)
2. Modifying the settings seems to work and updates well
3. My “Screen Options” and “Help” buttons in the up right corner doesn’t seem to work anymore; if I deactivate Hover they work like a charm.
4.I’ve tried to deactivate all the plugins in order to check for incompatibilities, but still doesn’t work
5. I suspect that it has something to do with the ajax (or the xajax functions), but i cannot detect what’s wrong.

Any assistance pls? 10x