a question about export with innobackupex

mysql version : percona 5.5.21
xbackversion : 2.1.3-608

step 1:

innobackupex -xx -xx /tmp/

step 2:

innobackupex --apply-log --export /tmp/path_to_backup/

step3, login mysql
alter table xx discard tablespace && cp /tmp/path_to_backup/table.exp table.ibd to datadir

step4 , chown user

step5, alter table xx import tablespace , the file size of ibd file is ok, but execute select * from table, return o rows.