I too was having problems on Firefox and I will NOT use Chrome. I think I may have found a fix/workaround for all you Firefoxers. It appears the Eno extension does not like multiple tabs open. I close Firefox and when it restarts I just go to the site I'm purchasing something from and Eno works. When I'm done I go to History>Restore Previous session and Firefox will load the 50 tabs I had open from before. I hope this works for you because Eno has become a part of my online process.