The way to view your browsing history is to go to History > Show All History. That should open the Library window. Do you remember if your history was cleared around 7 days ago?

Yes, that's what I did - "Show All History" . It only shows me 7 days worth of history, to within the hour (in other words, at noon today, the earliest history it showed me was 7 days ago at around noon. At 3pm, the earliest history it showed me was 7 days ago at around 3pm.)

I didn't personally clear the history - ever. However, I did have a Mozilla/Firefox crash about a week ago (can't remember exactly which day). Would such a crash cause Firefox to lose the history?

That's quite possible. Go to the address about:crashes and tell us your latest crash IDs. We can then look at the data specific to your crash and check if that type of crash is known to clear history.

Also, Firefox 3.6.4 was released today, which contains a crash protection feature. See http://blog.mozilla.com/blog/2010/06/22/firefox-3-6-4-with-crash-protection-now-available/

Here's the Report Id of the crash bp-88fb6df0-f801-48dd-9eb2-572942100611

Here's the ID of the report 88fb6df0-f801-48dd-9eb2-572942100611 The crash was related to viewing streaming video from ustream.tv

It may not apply - it's dated 6/11, while the earliest history date is 6/15. If the crash cleared my history, shouldn't I be able to see history back to the time of the crash on 6/11?

As it sits right now, I can no longer see the history of 6/15 (7 days ago) between noon and now (what I could see at noon and at 3 pm is no longer displayed), so it seems to me that there's some other reason that I can't see the history older than 7 days.

It's possible that you decided not to send a crash report for the week-old crash.

I looked up info for that crash signature and found nothing.

That is a problem with the Flash plugin. See http://crash-stats.mozilla.com/report/index/88fb6df0-f801-48dd-9eb2-572942100611

I understand that the crash was due to to Flash - but I still need to know why I can only see 7 days of history when my "save history for" duration is set to 30 days. How can I see my history beyond 7 days?

According to your troubleshooting info, you've got 2 modified preferences: browser.history_expire_days 7

browser.history_expire_days.mirror 7

In the Location bar, type about:config and press Enter . The about:config "This might void your warranty!" warning page may appear. Click I'll be careful, I promise! , to continue to the about:config page. Search for the preference browser.history_expire_days. Right-click on it, and select Reset. Do the same for the other preference.

Finding this info was an absolute pain! I want to KEEP my browsing history - I use the info to fill out time sheets etc for work and my new computer was throwing out everything more than 14 days old even though I had the "save history" feature set to 90 days.