dublicate entry in img_assist_map

Good evening,

Im using drupal 4.6.8. I`m getting a strange error when putting more than one image via img_assist into a textfield. After hitting "submit" for uploading the node I get the following:

Fatal error: Duplicate entry '7024-0' for key 1 query: INSERT INTO frightening_img_assist_map (nid, iid) VALUES(7024, 0) in C:\Programme\xampp\htdocs\frightening\includes\database.mysql.inc on line 66

When I put only one image into the field no error appears. I`ve also tried changing the input types, but the result is the same.