For the past several months, Firefox has been eating memory like crazy. Once I get more than 5 tabs open or have Firefox running for more than an hour or so, memory usage hits around one GB. If I keep letting it go beyond that, it'll hit 1.5-2 GB and it makes my whole desktop freeze up. I've taken to keeping Task Manager and every hour or so just kill Firefox and restart. That keeps it from crashing my whole desktop. It's definitely worse when I open Google products, especially Maps and Docs. GMail usually is OK. I have tried disabling literally every Add-On and Extension (including Flash and Adblock). I'm on Windows 7, I have 4 GB of RAM installed. I am on version 40.0 of Firefox, but this has been going on through a couple of updates now (I think the problem started around March or April). I also tried to back-rev Firefox and go to the last version I had before the problems started, but that didn't do anything either. Chrome works fine on this machine without any similar problems -- but I prefer Firefox!