RMAN-06749: restore point LAST_POINT does not exist.

I need to flashback database to restore point called last_point.
But there was an error during the flashback.
Look :

RMAN> list restore point all;

using target database control file instead of recovery catalog
SCN              RSP Time  Type       Time      Name
---------------- --------- ---------- --------- ----
39133655                   GUARANTEED 30-OCT-14 last_point

RMAN> flashback database to restore point last_point;

Starting flashback at 06-NOV-14
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=225 instance=dwh1 device type=DISK

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of flashback command at 11/06/2014 13:03:42
RMAN-06749: restore point LAST_POINT does not exist.

RMAN> flashback database to restore point "last_point";

Starting flashback at 06-NOV-14
using channel ORA_DISK_1
starting media recovery
media recovery complete, elapsed time: 00:00:03
Finished flashback at 06-NOV-14

RMAN> alter database open resetlogs;


If you know, the name of restore point must be in caps lock letters.
But in my case the name of RP was in small case.
The solution - to use " " for name.