Error edting and deleting frondend items

situation:

1. i created a usergroup "Support"
2. installed the new Component
3. grant access (create,delete,edit,esit state, edit own)  to usergroup "Support"
4. login as an user of the "Support" group

In the list-view the buttons for editing and deleting appear, but they do not work:

• afte clicking the "delete-Button - and "are you shure... - the component jumbs to the detail view of the lastest record, that was opened before

In the detail-view there is a 500-Error-page after clicking delete. When clicking on edit, the form opens: Record-id is correct but there are no other values.

Can you check this out?

Regards
Airo