Wow, such a fast reply by an Admin, I am honored
Well, my website is for a computer store, so the word "webcam" appears a lot!
Recently our web host changed security, and we've been having a lot of problems. We found this error when trying to update a laptop description (with the word "webcam", of course) and got a "403 forbidden" error.
After reading hopewell10's post, I tried adding a new product without that word, and it worked! The error only appears when "webcam" is in there (Title, short description, anywhere).
You can take a look at the website, if you'd like: http://entertirso.pt/
I wonder if I can ask the web host to change those black-listed words...
Thank you, anyway!