downthemall has stopped downloading

Suddenly the downthemall addon in Firefox browser has stopped downloading. Browser can download but downthemall can't. When I give it any link, it doesn't start and timeout after 5mins (timeout is set to 5min). It happens with any link (even with simple html pages). I have tried disable/enable, remove/install, firefox restart, pc reboot, but it didn't work. Anyone have any suggestions? P.S I can't delete cookies, they are too important.