Sitecore item deletes image on save

Question

We have a pretty large website running on sitecore 7.2. On a couple of items we noticed a certain problem. Everytime we link a picture to the item and we save it, the item is saved without the image.

The items are of the same template of 900 other items, so i don't think it's a template problem.

I can link the images on other items without a problem, so i can exclude these too. (i think)

When i search the logs, nothing is found. No ERROR can be found.

Can someone help me in this problem?

EDIT

After searching in the database for the records, i found these:

Answer 1

You need to get the ghost value out of Sitecore's "shared fields". For the item ID's in question, take a look at the [SharedFields] table in your "master" database.

SELECT * FROM [SharedFields] WHERE [ItemId]='your item id' AND [FieldId]='your field id'

If I am right, you will find values here. If the field is no longer shared, these should be safe to remove.

Always though, when messing directly with the database, backup etc. :)