From http://www.immigration-law.com/Canada.html.
11/07/2006: Multiple Labor Certification Filing Alert
There are growing number of reports that the BEC was sending out a "
withdrawal" notice to the employer if the same employer filed a PERM
application for the same job and the same alien "if" prior old priority date
labor certification is pending at the BEC for the same employer for the
same employee and for the same job. This withdrawal notice was sent out even
if the employer did not request "
