I received the following error while duplicating database using RMAN. The command executed was
RMAN> duplicate target database to cool;



The error stack at the end is:

starting media recovery

archive log thread 1 sequence 605 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00605.001
archive log thread 1 sequence 606 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00606.001
archive log thread 1 sequence 607 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00607.001
archive log thread 1 sequence 608 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00608.001
archive log thread 1 sequence 609 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00609.001
archive log thread 1 sequence 610 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00610.001
archive log thread 1 sequence 611 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00611.001
archive log thread 1 sequence 612 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00612.001
archive log thread 1 sequence 613 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00613.001
archive log thread 1 sequence 614 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00614.001
archive log thread 1 sequence 615 is already on disk as file E:\ORACLE\ARCHIVE\O
RCL\ARC00615.001
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00605.001 thread=1 sequence=605
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00606.001 thread=1 sequence=606
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00607.001 thread=1 sequence=607
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00608.001 thread=1 sequence=608
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00609.001 thread=1 sequence=609
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00610.001 thread=1 sequence=610
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00611.001 thread=1 sequence=611
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00612.001 thread=1 sequence=612
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00613.001 thread=1 sequence=613
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00614.001 thread=1 sequence=614
archive log filename=E:\ORACLE\ARCHIVE\ORCL\ARC00615.001 thread=1 sequence=615
unable to find archive log
archive log thread=1 sequence=616
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of Duplicate Db command at 05/04/2009 21:01:57
RMAN-03015: error occurred in stored script Memory Script
RMAN-06054: media recovery requesting unknown log: thread 1 scn 6228235



On target database, the following command's output is:
SQL> select group#,sequence#,status from v$log;

GROUP# SEQUENCE# STATUS
---------- ---------- ----------------
1 616 CURRENT
2 614 INACTIVE
3 615 INACTIVE

SQL>


Then I tried to open the duplicate database using resetlogs option and it opened successfully.

Should such a thing happen?