Better double check your relationships in Manage | Database | Relationships. It sounds like you are getting a cascading delete due to one or more relationships that have a "delete" option specified that should be specified.
Yes, you were right. Thanks!!!
I had the relationship check box set to delete records in this table when other record is deleted ...
I unchecked this, did the delete found group, and it only deleted the found group.
This option is very powerful and thus both very useful when set up correctly, but very dangerous when set up incorrectly.
I've recently decided that it Makes sense to click the A tool in Manage | Database | Relationships to add a Note box for listing all relationships that have this delete option selected just to make it easier to keep track of that option.