Firefox browsing history: strange setting behaviour

I noticed that the location bar in Firefox (3.6) became less responsive the last weeks. I figured it was due to a too large history list, so I decided to make it shorter.

In the privacy options of Firefox there is an entry "Remember my browsing history for at least x days" which defaults to 90 days. However, when I checked my history list, to my surprise there where entries under "history older than 6 months", which is definitely longer than 90 days.

Question: Why does it keep history longer than the specified number of days (what's the point otherwise of specifying it)? Related, why does it say "... at least x days..."? If I set it to 30 days, I would it expect it to delete history entries as soon as they become 31 days old, not keep them.

(BTW: cleaning the history list solved the location bar sluggishness, but that's not the issue here)

Solution 1:

Try checking the values for these by typing about:config in your address bar.

browser.history_expire_days

http://kb.mozillazine.org/Browser.history_expire_days

browser.history_expire_days_min

http://kb.mozillazine.org/Browser.history_expire_days_min

browser.history_expire_sites

http://kb.mozillazine.org/Browser.history_expire_sites

Note: Pages expire after X days, but they only do it on shutdown..

This could be a bug. Though there was also a bug earlier, which i think has been resolved. https://bugzilla.mozilla.org/show_bug.cgi?id=55293