arejfour, what version of Firefox are you using? I've been having a similar problem since I updated from 3.0 to Shiretoko/3.5 (I run nightlies, so now I'm on 3.5.1pre, but this started with 3.5pre) - if I run CCleaner with all Firefox options except for Saved Form Information checked, I lose my smart location bar/Awesomebar frecencies. For example, I used to get planet.mozilla.org to pop up first in my Awesomebar results when I typed in "pla", as I visit that site at least once a day, but now after CCleaner runs (and it runs on reboot), it ends up in the middle of results list, and doesn't even come up until I type in "plan". The same settings in CCleaner don't seem to affect my Minefield 3.6a1pre installation/profile, and I have the same exact settings for Clear Recent History set in both profiles. I had Firefox set to Clear Recent History on exit, and I was clearing pretty much everything before and after upgrading. After some testing, I found that if I also uncheck Internet History in CCleaner, my Awesomebar frecencies are saved. This might fix your problem also, for now. If it does, then there's a bug somewhere between the two programs, I guess.