I had the same thing happen to me a few versions ago. Fortunately I had an old copy of bookmarks.html around.
My solution was kinda crazy, I started using del.icio.us
(which was recently bought by Yahoo! btw) to store my bookmarks instead.
I know that's not exactly a ringing endorsement of Firefox, but while I did really like my "bookmark hierarchy", ontologies are overrated
and I found that no matter which browser I used, after I reached a certain minimum # of bookmarks it just became unusable.
I know it sounds crazy, but believe it or not, the flat "tag" based organization method actually seems to work better so far than all those nested Firefox (or even IE) bookmarks ever did. And I get the added benefit that I can access and add/edit the bookmarks from anywhere.
Plus, I can use my tags as a basis to find other people's
bookmarks, which is a neat way to delve into a topic of interest. For example, you can view all del.icio.us users' bookmarks for cthulhu
, or discordia
Anyway, it's pretty disappointing that a bug like this (erasure of bookmarks) would still exist. That is
the kind of thing that seriously erodes one's confidence in a product. And I wrote as much in the bug report I filed on it a year or two ago (wish I could find it now).
However, on the whole it still kicks the ass of the competition, at least IE (I can't speak to Opera or Safari, though AFAIK Opera is still payware to avoid annoying ads, and Safari is Mac only). I think the old Mozilla browser (combined e-mail, browser, etc.) still exists too, though it might be under a different name
It's got its challenges, certainly, but it's so far ahead of the competition that I'll find ways around its few flaws just to have all the other great features it has, not to mention the inherent "fight the power" aspect of the whole thing ("take back the web" and all that :)