Datapump on Windows Platform

I was trying to do an impdp on a windows platform but I got the follwoing error:

ORA-39002: invalid operation
ORA-39070: Unable to open the log file.
ORA-29283: invalid file operation
ORA-06512: at "SYS.UTL_FILE", line 475
ORA-29283: invalid file operation

The obvious answer seems to be the Oracle Directory is not created or is missing read/write priviliges. However this was not the case. as teh following query showed:

SELECT d.owner,privilege, directory_name
FROM user_tab_privs t
, all_directories d
WHERE t.table_name(+)=d.directory_name
ORDER BY 3,2

The problem is that the directory was created using a mapped network drive which was mapped after Oracle was started. Oracle therefore could not read teh directory.
See:
Metalink : Doc ID: Note:221849.1

Symptom(s)
ORA-29283 Invalid file operation when accessing file on a mappeddrive using utl_file package

Cause
The reason for this error is because Oracle service isstarted using system account(default) which doesnt haveprivilege in the mapped folder.