When to restore controlfile, rman is complaining database not mounted?

Question

to restore controlfile, shouldn`t the database be in NOMOUNT status?
if yes, then why rman is complaining ORA-01507?
where I went wrong? Please advise.
C:\Documents and Settings\PhoenixBai>rman target / nocatalog
Recovery Manager: Release 10.2.0.1.0 - Production on Tue Dec 14 10:35:51 2010
Copyright (c) 1982, 2005, Oracle.  All rights reserved.
connected to target database (not started)
RMAN> startup nomount;
Oracle instance started
Total System Global Area     612368384 bytes
Fixed Size                     1250428 bytes
Variable Size                234883972 bytes
Database Buffers             369098752 bytes
Redo Buffers                   7135232 bytes
RMAN> restore controlfile until time 'sysdate-1.5/24';
Starting restore at 14-DEC-10
allocated channel: ORA_DISK_1
channel ORA_DISK_1: sid=157 devtype=DISK
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 12/14/2010 10:36:12
ORA-01507: database not mounted
RMAN>

Answer 1

it doesn`t. I tried long before this one.
the dilemma i am facing is that I need to recover to the time which was included in incarnation 2.
And to be able to reset database to incarnation 2, i need to startup MOUNT the database.
And once you startup mount the database RESTORE CONTROLFILE won`t work any more.
below is the standard procedure, documented on 10gR2 doc, but still, i am getting errors:
Why it is throwing errors? HOw can I fix?
RMAN> alter database mount;
database mounted
RMAN> list incarnation of database orcl;
List of Database Incarnations
DB Key  Inc Key DB Name  DB ID            STATUS  Reset SCN  Reset Time
1       1       ORCL     1264908153       PARENT  1          30-AUG-05
2       2       ORCL     1264908153       PARENT  534907     07-DEC-10
3       3       ORCL     1264908153       CURRENT 56335397   14-DEC-10
RMAN> reset database to incarnation 2;
database reset to incarnation 2
RMAN> restore database until scn 56335390;
Starting restore at 14-DEC-10
using channel ORA_DISK_1
creating datafile fno=6 name=E:\ORACLE\PRODUCT\10.2.0\ORADATA\ORCL\ETLTBS01.ORA
channel ORA_DISK_1: starting datafile backupset restore
channel ORA_DISK_1: specifying datafile(s) to restore from backup set
restoring datafile 00001 to E:\ORACLE\PRODUCT\10.2.0\ORADATA\ORCL\SYSTEM01.DBF
restoring datafile 00002 to E:\ORACLE\PRODUCT\10.2.0\ORADATA\ORCL\UNDOTBS01.DBF
restoring datafile 00003 to E:\ORACLE\PRODUCT\10.2.0\ORADATA\ORCL\SYSAUX01.DBF
restoring datafile 00004 to E:\ORACLE\PRODUCT\10.2.0\ORADATA\ORCL\USERS01.DBF
restoring datafile 00005 to E:\ORACLE\PRODUCT\10.2.0\ORADATA\ORCL\EXAMPLE01.DBF
channel ORA_DISK_1: reading from backup piece E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\ORCL\BACKUPSET\2
MF_NNND1_TAG20101213T132300_6JCCFO2X_.BKP
channel ORA_DISK_1: restored backup piece 1
piece handle=E:\ORACLE\PRODUCT\10.2.0\FLASH_RECOVERY_AREA\ORCL\BACKUPSET\2010_12_13\O1_MF_NNND1_TAG20101213
O2X_.BKP tag=TAG20101213T132300
channel ORA_DISK_1: restore complete, elapsed time: 00:00:55
Finished restore at 14-DEC-10
RMAN> recover database until scn 56335390;
Starting recover at 14-DEC-10
using channel ORA_DISK_1
starting media recovery
media recovery failed
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of recover command at 12/14/2010 11:36:14
ORA-00283: recovery session canceled due to errors
RMAN-11003: failure during parse/execution of SQL statement: alter database recover if needed
start until change 56335390
ORA-00283: recovery session canceled due to errors
ORA-38727: FLASHBACK DATABASE requires a current control file.Edited by: PhoenixBai on Dec 14, 2010 11:37 AM