IIS Error, Stand-alone CA under Windows 2003

Hello,


I have a Windows 2003 running a stand-alone CA.
When I try to request a Client Auth. Certificate and export the keys to a
file I get an error 0x00000046 "You do not have write permission for this
file".
I try to export in temporary directory like e:\temp. I've checked everything
and i have put on all the NTFS permission .
I don't understand why i can't write in this directory via the in the Web CA
Interface.
I am logged in as an Administrator when requesting the cert.


Does someone have any ideas, for this problem?


Thanks a lot
fabrice