Product Version = NetBeans IDE Dev (Build 201110120600)
Operating System = Windows XP version 5.1 running on x86
Java; VM; Vendor = 1.7.0
Runtime = Java HotSpot(TM) Client VM 21.0-b17

I created a new class. Since I could re-use some code from an other class file, I wanted to perform a copy-paste operation [copy-paste-loose :-)]

@Entity
@Table(name = "Account", catalog="WebRequest", schema="dbo")
public class Account implements Serializable {

    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "acId")
    private Integer _accountId;

Text above is what I copied with ctrl-c into clipboard. And this is what I got after inserting:

@EntityEntity
@TableTable(name = "Account", catalog="WebRequest", schema="dbo")
public class Account implements SerializableSerializable {

    private static final long serialVersionUID = 1L;
    @IdId
    @GeneratedValueGeneratedValue(strategy = GenerationTypeGenerationType.IDENTITY)
    @ColumnColumn(name = "acId")
    private IntegerInteger _accountId;

All annotation names had been doubled and the Integer type too.