Why is my Banner Manager button missing from the Tool drop down menu?

Hello all!
I have a weird question. I just installed Zen Cart 1.3.9d and my Banner Manager button is missing from the Tool drop down menu.
Can someone help me please? I couldn't find an answer anywhere. I double checked all the files with "banner" in the title to make sure they're copied correctly and are in the right folders. i initially found two doc missing from the Admin directory (banner_manager.php and banner_statics.php) and i copied them again thinking this would do the trick. but still no.
I can tell where the "Banner Manager" button should be, cuz on the Tool's drop down menu, there is a thicker gray line between the "Layout Boxes Controller" and "Send Email". When i click on Tool, there's a bullet point missing between the above two categories.

I don't what did to make the button go away. Now how can i get it back??

Thank you so much for helping!!!!!

im not really sure
all i know is that when i installed 1.3.9d the admin area wasnt displaying right at all. i asked here, no one got back to me. i just deleted it and installed 1.3.9e
all the best

Thank you for responding! I'll try reinstall it.

Anyone figured out which files caused this. I'm seeing it now on one my sites and the only update we did was to add the Google Data Feed. Doesn't seem like it should cause a problem.

Ready for a bizarre answer.

I was using the AdvertBan plugin for FireFox. It suddenly started blocking the word "banner" from appearing. Not only was Banner Manager missing from the Zen tools, the tables were not visible to me in phpMyAdmin.