xb_export test fails

CentOS 5.5 x86_64
Percona Server 5.1.55-rel12.6
xtrabackup Ver 1.6 Rev 245

Test t/xb_export.sh fails. When we use xtrabackup for prepare with --no-defaults option, we should explicitely specify option --innodb_file_per_table to make export feature working. This fact is not mentioned in docs.

Backup contains tables in their own .ibd files.
Part from log:

2011-04-12 19:44:37: xb_export.sh: ===> xtrabackup --no-defaults --datadir=/root/percona-xtrabackup/test/var/mysql --prepare --export --target-dir=/root/percona-xtrabackup/test/var/xb_export_backup
xtrabackup: cd to /root/percona-xtrabackup/test/var/xb_export_backup
xtrabackup: This target seems to be not prepared yet.
xtrabackup: Temporary instance for recovery is set as followings.
xtrabackup: innodb_data_home_dir = ./
xtrabackup: innodb_data_file_path = ibdata1:10M:autoextend
xtrabackup: innodb_log_group_home_dir = ./
xtrabackup: innodb_log_files_in_group = 1
xtrabackup: innodb_log_file_size = 2097152
xtrabackup: Starting InnoDB instance for recovery.
xtrabackup: Using 104857600 bytes for buffer pool (set by --use-memory parameter)
InnoDB: The InnoDB memory heap is disabled
InnoDB: Mutexes and rw_locks use GCC atomic builtins
InnoDB: Compressed tables use zlib 1.2.3
InnoDB: Warning: innodb_file_io_threads is deprecated. Please use innodb_read_io_threads and innodb_write_io_threads instead
110412 19:44:37 InnoDB: Initializing buffer pool, size = 100.0M
110412 19:44:37 InnoDB: Completed initialization of buffer pool
110412 19:44:37 InnoDB: highest supported file format is Barracuda.
InnoDB: Log scan progressed past the checkpoint lsn 38470
110412 19:44:37 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Doing recovery: scanned up to log sequence number 58034 (1 %)
110412 19:44:37 InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percents: 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
InnoDB: Apply batch completed
110412 19:44:37 Percona XtraDB (http://www.percona.com) 1.0.15-12.5 started; log sequence number 58034
xtrabackup: starting shutdown with innodb_fast_shutdown = 1
110412 19:44:37 InnoDB: Starting shutdown...
110412 19:44:38 InnoDB: Shutdown completed; log sequence number 58034
xtrabackup Ver 1.6 Rev 245 for 5.1.55 unknown-linux-gnu (x86_64)
xtrabackup: xtrabackup_logfile detected: size=2097152, start_lsn=(38470)
xtrabackup: export option is specified.
xtrabackup: export option is for file_per_table only, disabled.