When I first started using firefox, I was using the restore tabs feature, so when I shut down my computer and reopened it I would find myself back where I started. With time I had a lot of tabs open across multiple windows. One day I lost these tabs when I opened my computer, I'll call these tabs set one. I didn't use the restore feature, since I figured I would just restart and maybe manage my tabs, so I started fresh and start a new set of windows. This set obviously went the same way, lots of tabs over a few windows, that restore when I open firefox on my computer. This is set two. But every so often now I'll turn on my computer and find that I am on a different set. My previous collection of open tabs is back and while I can see in my history what I have searched, there is no option to restore the previous set of windows. It's not often, maybe once every few weeks, but it will switch between the two sets of tabs. It's annoying because I am working with these tabs so if I am back on a previous set, then I need to reorganize my windows. Anyone had this issue?