Fieldgroup field removed from fieldgroup in all node types

If you use the same field on multiple node types (multiple instances of the same field) and that field is in a fieldgroup on multiple node types, when you remove the field instance from any one node type, it will remove the field from fieldgroups in other node types.

To me it appears this is the problem:

In function: fieldgroup_content_fieldapi
SQL: DELETE FROM content_group_fields WHERE field_name = 'field_test_number'

this should be

SQL: DELETE FROM content_group_fields WHERE field_name = 'field_test_number' AND type_name = 'test_node_type'