I have Firefox version 2.0.0.10 on OpenSUSE 10.3. I have organized all my bookmarks. Very recently, without disturbing myFirefox setting, I have installed SeaMonkey version 1.1.8. Bingo! All my bookmarks in Firefox disappeared. Is there anyway to restore? And why it is happening, though I did not do anything on Firefox setting?

The bookmarks (for Firefox and Seamonkey) are a file named bookmarks.html in the ${HOME}/.mozilla directory tree.

The Seamonkey file is in ${HOME}/.mozilla/default/secret_code.slt/bookmarks.html and the Firefox file is in ${HOME}/.mozilla/firefox/secret_code.default/bookmarks.html.

If you lost those, you're cooked (and there's no reason that installing Seamonkey would wipe out the Firefox bookmarks file). Use the find utility in your home directory; e.g., find .mozilla -name 'bookmarks.html' to see if it still exists somewhere and, if it does, look at the .mozilla directory and see what's there. If you've still got your Firefox bookmarks file, you can simply copy it to the Seamonkey tree but check that the structure looks like the above and that there is a size to the bookmarks.html file before you do!

As an aside, if you're using Thunderbird, you can copy the .thunderbird/secret_code.default/abook.mab file to .mozilla/default/secret_code.slt/abook.mab and you'll have your address book in Seamonkey.

Firefox has a folder 'bookmark_backups' in
${HOME}/.mozilla/firefox/secret_code.default/

The folder ${HOME}/.mozilla/firefox/secret_code.default/ is not existing in the directory. The home directory contains:

/.mozilla> ls
appreg default firefox pluginreg.dat

ls firefox/
pluginreg.dat profiles.ini wlie9uxq.default

ls firefox/wlie9uxq.default/
bookmarkbackups compreg.dat history.dat secmod.db
bookmarks.bak cookies.txt key3.db signons2.txt
bookmarks.html extensions localstore.rdf urlclassifier2.sqlite
Cache extensions.cache mimeTypes.rdf XPC.mfasl
cert8.db extensions.ini prefs.js xpti.dat
chrome extensions.rdf search.rdf XUL.mfasl
compatibility.ini formhistory.dat search.sqlite

Is it the folder 'wlie9uxq.default' equivalent to the 'secret_code.default'? Any way after examining the 'bookmarkbackups' folder I found the HTML files but of no use.

One thing I did not mention earlier is I installed and uninstalled Mozilla before installing the SeaMonkey. I guess during this process, I might have erased the bookmarks myself instead of the SeaMonkey.

Yes, wlie9uxq is "secret_code;" whenever and user begins using a newly-installed Firefox, Thunderbird or Seamonkey that code is generated specifically and uniquely for that user and that package initialization. I just used "secret-code" to represent the unique code.

It's quite possible that uninstalling Firefox (Mozilla?) did away with your bookmarks file (although I can't imagine why that would happen). Normally, you would simply install a new package (Firefox and Seamonkey co-exist quite nicely) alongside another Mozilla package without removing or uninstalling anything.

Just for future reference, make back up copies of bookmarks.html and abook.mab (in Thunderbird and Seamonkey) every so often...

Best of luck with it.