I have created a Home profile and a Work profile in Firefox and use the add-on ProfileSwitcher to switch on the fly, so when I am at work I can access the history and bookmarks (bookmark bar menu) I use at home, and vice versa. But I keep them separate. I keep extensive bookmarks in folders on the bookmark bar menu to aid in productivity. The problem is that recently my Firefox at work exhibited a "glitch" of some kind and Firefox lost both profiles. I thought this was no problem. Sync. The next time I did a sync, both the histories and bookmarks from home and work became combined into one "default" profile on my work machine. I was worried about syncing my home computer lest the same thing happen I created matching profiles again, did a sync, and manually removed my bookmarks (from the graphical bookmark menu bar) from each profile. I am afraid I have lost any new bookmarks I have created over the last few days at home and I am afraid to sync my home Firefox. I do not understand how sync works when the two profiles do not match. Does it "add?" Does it "delete?" How does it decide which profile is newer, and how do I prevent a "glitch" from ruining the profile in the other location when the next sync occurs?