Thank you for your post.
The keyboard commands "D" and "C" in the Delete Record dialog box was removed in FileMaker Pro 11 to comply with Mac OS X. I encourage you to enter this as a suggestion into our Feature Requests web form at:
The entries from this web form are automatically populated into a database file that is hosted by Development and Product Management, where the entries are then discussed and considered for a future release. Although I could copy your post and paste it into the web form, there are a couple of questions asked that only you can answer.
In the mean time, you can either press Command-option-E to delete the record without the dialog box appearing, or press Command-E and then click on Delete or Cancel.