I keep getting a message that says I may have a pop up blocker on when I have turned it off.

I am taking an online class and on some slides I have to place the cursor over an area to reveal additional information. when I do this it goes well. On other occasions I must click on a portion to the slide to open additional information. There is a note at the top of the new information that reads click to return to the program. When I do this I am sent to a screen that reads I may have a pop up blocker and alloys me the chanch to click on FireFox to turn off the bolcker. I turned off the blocker and still get the screen.