Hi ziggar.uk. Thank you for spotting the issue. I have made a quick fix for Facebook, which should work for eBay too. It's in version 1.3.1, which is now in the addons.mozilla.org review process and should be available soon. If you have Rotate and Zoom Image still installed, just try to update it https://support.mozilla.org/kb/how-update-add-ons

If you still see the issue, please contact me directly via the support email on the right side of this page.

EDIT: The new version is now approved and available for update/install.