If a page with an embedded image in a custom tag is edited, the online editor removes the image from the custom tag.

Steps to reproduce

1. Create a object
1.1 Create a factbox
1.2 Include an image in the factbox
1.3 Publish this object
Result: => When published the object is correctly stored.

2. Edit the object again in editor mode (with editor mode turned off, the image is still included)
Result: => Factbox does not contain an image