When adding a watermark image, the images located outside eZ IE extension (extension/<my ext>/design/standard/images/watermarks) are not working.

Note that it works correctly for preview but not when really applying it.

Steps to reproduce

• add a new watermarl image inside your own extension
• declare it inside iamge.ini
• edit an image and add the watermark
• apply and save
  => watermark is not added.

Note also that error log clearly reference a non existing image inside ezie extension instead of you own extension