Twice in the last coupla week now my bookmarks on firefox are gone when I restart my computer. And they don't come back. I even did a system restore and they still didn't come back. What could be causing this?
I'm not too sure, but I think it has to do with the Windows version -- back when I had Windows the same thing happened to me a couple of times, but since I switched to GNU/Linux it hasn't. Never figured it out.
Luckily, Firefox keeps a backup of your bookmarks, so you might be able to recover some of them by going to the backup folder. Don't recall exactly where it is in Windows (Application Data, maybe), but here's where it is in Linux, if it helps:
The "123456" is a substitute for the seemingly randomly generated name that Firefox gives your profile. Not sure what yours will be.
Anyway, once you find the backup folder, you can move the most recent backup to the main profile folder, and replace the "bookmarks.html" file. That's where the active bookmarks are stored.
Supposedly, this entire process will change with Firefox 3.0, which is supposed to support a bookmark database, so you could conceivably synchronize your bookmarks across multiple PCs from one place.