Bookmarks shouldn't get deleted by using Delete browsing, search and download history on Firefox. If you have visited a bookmarked site and you clear the history then only that history item will be removed, but not the bookmark itself. Of course you reset the visit count by deleting the history, so items that show in the location bar drop down list will change.

I want to keep starred bookmarks, but clear everything else at end of browsing session, history, cookies, cache, etc. Was able to do this with earlier version of Firefox.

Any suggestions would be greatly appreciated.

That´s correct Cor-el, bookmarks shouldn't get deleted when using any other feature than managing bookmarks. I can say I've been using Firefox for a long time and this is the first time I see this behavior.

At the beginning I thought was something i did by mistake. The next time it occurred to me I wasn't sure because sometimes I use portable Firefox and I bookmark some sites there too.

Finally I discovered this is only happening in the installed version of my HP pavilion dv4la

MS Windows 7 Home premium 64-bits

Mozilla/5.0 (Windows; U; Windows NT 6.1; es-MX; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3

I noticed this is the Spanish version and Jack's English version is having the same behavior.

The only thing I can say is that bookmars don´t "vanish" during the sesion but after closing and opening Firefox back. Unfortunatelly this is not happening all the time so I can't see any pattern so far.

See http://kb.mozillazine.org/Locked_or_damaged_places.sqlite