[Gretl-users] problems after upgrading to ubuntu 16.04

Dear all yesterday i upgraded from 15.10 to 16.04. I immediatly ##SELECTION_END##noticed a great lack of performance (is impossible charge large databases and perform scripts that last week where trivial). So i decided to remove the package and reinstall it. I tried to do it with the Ubuntu Software Center, and it didnt worked (but only for Gretl, other softwares are well managed). I mean, in the software center i see both Gretl icon and the "remove" button,  but if i push it there is no effect. So i tried from the terminal.  I was very surprised when i read the answer after the sudo command:  Gretl was NOT installed. But of course there is a copy working and i can use it for limited task.  The directory where i see all the folders (even after the terminal command of deletion) is the classic Home\gretl\. So at the moment i have a badly working Gretl located and no chance to delete and reinstall it. Any suggestions? Thx. Guido