Adblock plus not working?

[Annie]

For a couple weeks now, I have been getting relentless popup ads on almost every website I visit. A lot are from "onlinewebfind.com" or "luckysavings". Some are pop up windows, others are entirely new tabs. It's INCREDIBLY annoying. Sometimes I get them when I click a link, and sometimes it's even just when I click anywhere on the page. I have Adblock Plus, and it says it's enabled, and I'm pretty sure I have the latest version of Firefox. Why has this started happening? Someone please help, this is getting very tiring.