Lot more info will be needed. What OS you are using, what browser version what version of ABP, what other extensions (add-ons) and as much info as you can give out about your setup and even what ever might have changed lately.
same problem here. noticed ab had stopped working yesterday. tried dis-enable and enable tried reinstalling only when I try to manually add a filter I am told that ABP has been disabled otherwise it says everything is A-OK...
I'm running Ubuntu 10.04 LTS firefox 3.6.13 and the latest ABP
I'm noticing the exact same problem here. I hadn't upgraded my browser or made any other changes that might have prompted it. It just all of sudden wasn't working. The icon doesn't appear in my browser, even though AdBlock Plus is showing up in my list of add-ons, and ads are no longer being blocked. I've tried disabling and enabling, installing and installing, restarting my computer -- nothing works.
OS: Windows Vista Firefox 3.6.13 Other ad-ons: Zotero Leechblock BarTab Better GReader Organize Status Bar Session Manager