For More Information see: Unable to import Bento database
This is one of many acknowledged bugs that can be found in the Known Bug List here in the Report an Issue section of the forum.
It can also be downloaded as a database file from: http://www.4shared.com/file/8orL8apk/FMP_Bugs.html
Thank you for your post.
This was caused by the Bento 3.0.5 update. However, we recently released Bento 3.0.6 which again allows FileMaker Pro to import a Bento Data Source. You can download the Bento 3.0.6 updater via Knowledge Base Article #7861 at: