Hi,
from your infos I would have a look at permissions first.
Could it be that the application pool user from the default web site is different to your special web site? If yes, could it be that this user does not have access to the E:\ directory?
Error 5 (of 0x8???4005 or similar error numbers) in the MS world is nearly always an indicator of rights problems, because it originates from the OS error 5 "access denied"...
WM_JUSTMY2CENTS
Günter from Frankfurt/Germany