System Error when thumbnail image has comment with String charachter " and numbers

An mysteriously Error:

You attach an image to a page and give the following comment: This is the "image" 1.
Place the image in a page as thumbnail

!Blue hills.jpg|thumbnail!

and save the page.
Edit the page, switch to RichText Editor and then try to switch back to the Mark Up Editor. No way.
Then try to save the page.

System Error
org.w3c.dom.DOMException: INVALID_CHARACTER_ERR: An invalid or illegal XML character is specified.
at org.apache.xerces.dom.CoreDocumentImpl.createAttribute(Unknown Source)

If you edit the comment and delete the number or delete the string signs " or display the image not as thumbnail, there is no problem!