Lswitch!!! This was what i was loocking for times ago, thanks Pete, i remember it but not the widget for eCenter! This solve definitively my problem (seems to me that David have the same problem than me with the windows list widget) without reinstalling all!! Now i have only one more desktop (the duplicate one got trying to solve the problem and the previous which has all my personal settings: i should restore manually deleting/moving them to the new one.
But I still have the question: how is it possible? how occur/solve it?
Regards.