I backed up my profile on an XP64 bit machine and moved it to the same version, 29.0.1, of FireFox(FF) on a Win7-64 OS. Tabs won't reload after creating a new profile and copying the files in to the profile directory. What does happen is a new sessionstore.js file gets created each time I start FF and the file I would like it to open gets renamed sessionstore.bak with a numerical date string in the extension. I can use NotePad to open the file and there is a ton of code in there and I even tried to copy and paste it into the the new sessionstore.js file that FF keeps creating and saving it in Unicode format. No luck :( I thought this would be a simple a straight forward transfer of my profile to a new machine. PS. Even the Bookmarks didn't open and I had to use a BackUp and Restore but at least that was a simple enough manual operation.